Planning

Each outcome in VCE Physics draws on a set of key science skills listed on pages 11 and 12 of the study design. The development, demonstration and application of the key science skills must be integrated into a teaching and assessment program and applied in a variety of contexts, including through practical work. A number of approaches to teaching and learning can support the development, demonstration and application of key science skills, including a focus on inquiry where students pose questions, explore scientific ideas, draw evidence-based conclusions and propose solutions to problems. An appropriate balance of theoretical and practical activities should be included in teaching and assessment programs.

Students should be expected to demonstrate progressively higher skill levels across Units 1 to 4. Teachers are encouraged to map the specific teaching and assessment of the Units 1–4 Physics skills across all units, ensuring that all key science skills are covered in the delivery of a program of study and that skills are covered at progressively higher levels. Making explicit to students when and how they are developing each of the Units 1–4 Physics skills can also facilitate student-directed learning and encourage students to self-monitor their successful achievement of each skill.

To assist in planning, teachers may access the VCE Physics Units 1 and 2 key science skills mapping grid and the VCE Physics Units 3 and 4 key science skills mapping grid. Examples of teaching and learning activities that include the development, demonstration and application of key science skills integrated into key knowledge have been provided in the Teaching and learning activities and in the Sample teaching plans.

Literacy in VCE Physics

VCE Physics involves learning technical language and understanding data representations related to the behaviour of physical phenomena in the Universe.

Information sources related to physics use a range of representations such as diagrams, tables, graphs, charts, photographs, video sequences, simulations and text to describe physics concepts and phenomena. Teachers are encouraged to support student learning of this multi-modal language by unpacking how each representation works in using multi-literacies (text and images) to develop explanations of physics concepts and phenomena.

Strategies for supporting students’ development of literacy in science include:

• providing students with opportunities to read, view, write, speak and listen to a wide range of texts and media to source and compare information, including traditional textbooks and online journals in addition to news websites and blogs, videos and social media channels
• students generating representations and explanations that illustrate student thinking in ways that allow the teacher to clarify and provide feedback
• teacher-guided and collaborative construction with students of different scientific explanations, illustrations and data representations, enabling students to compare and evaluate information from different sources to understand how ideas can be represented in different ways and to distinguish between scientific and non-scientific ideas.

Scientific literacy

Scientific literacy refers to peoples’ understanding of scientific concepts, phenomena and processes, and their ability to apply this knowledge to new and, at times, non-scientific situations (PISA, 2018). This involves students:

• being curious and asking, investigating or determining answers to questions generated from their observations about everyday experiences
• describing, explaining, hypothesising and making predictions about scientific phenomena
• critically evaluating the quality of scientific information and data on the basis of its source and the methods used to generate it
• identifying scientific issues underlying local, national and global issues and decisions, and expressing their own views that are based on scientific and technological understanding
• understanding and evaluating articles about science in the public domain and discussing the validity of the conclusions
• proposing arguments based on evidence and drawing valid conclusions from data.

Strategies for supporting students’ development of scientific literacy include:

• students working collaboratively and ethically in practical activities and discussing observations and results
• students participating respectfully in group discussions and debates
• continual questioning and inquiry, encouraging students to make observations, to question the ‘how’ and ‘why’ of science-related phenomena, and trying to make sense of them using their knowledge and research.

Students enter Units 1 to 4 VCE Physics with a range of ideas and preconceptions about phenomena in the real world. Alternative conceptions, sometimes called misconceptions, are the ideas that students have about scientific concepts that do not match with the generally accepted scientific explanation of those concepts. These alternative conceptions are often highly resistant to change which may therefore impact student learning.

Science education research has found that students need to address their alternate conceptions themselves by working with scenarios that refute their original conceptions and allow them to construct an improved mental model of the scientific concept. Using a direct teaching approach to simply inform students where they are going wrong has not been found to be effective in displacing alternative conceptions. Teaching strategies that enable alternative conceptions to be challenged involve probing student thinking, making reasoning visible, and providing prompt and specific feedback. Concept mapping, use of analogies, cognitive conflict, Socratic seminars, laboratory work, meta-learning, small group discussion and class discussion may be useful in exploring student thinking and ideas.

Monash University has designed a set of Conceptual Understanding Procedures (CUPs) relevant to VCE Physics. These CUPs are designed to facilitate the development of understanding of physics concepts that students find difficult. They are set in real-world rather than idealised or contrived situations so that students may explore physics ideas in authentic contexts.

The educational literature contains numerous examples of alternative conceptions. Further background reading about alternative conceptions and how they may be addressed in the classroom can be accessed at:

• Physics Teacher Education Program
• Institute of physics

The Learning activities across Units 1 to 4 include examples of CUPs and identified alternative conceptions that can be used as the basis of class discussions for each area of study.

Teachers are advised to provide students with learning opportunities that allow students to critically evaluate the stories, claims, discoveries and inventions about physics they hear and read in the media and to examine the relevance of science in their everyday lives. New and innovative contemporary research and ideas have been infused throughout the Teaching and learning activities.

Sources of information

Although original physics research reports are accessible, many require subscription, and most are written for a research audience. For the purposes of VCE Physics, teachers and students may access reports, videos and summaries of contemporary physics research and expert commentary through popular science publications (for example, Cosmos, The Scientist, and Scientific American), general interest resources such as The Conversation and online science media outlets where areas of interest can be filtered (for example, ScienceAlert and Science Daily, and back issues of Australasian Science). A range of other science organisations such as ABC Science, CSIRO and Museums Victoria also provide access to contemporary scientific research via email subscription.

Other sources of information include:

• Media products such as podcasts and webinars that enable students to communicate with physicists, enabling students to see the passion and skills scientists have for their field / research. Scientists may discuss the practical challenges and solutions (if available) and the potential of their research or project findings
• Citizen science programs that may be available both locally and internationally. Organisations such as the Australian Citizen Science Association and NASA include programs suitable for VCE Physics students across Units 1 to 4, for example, AstroQuest (to identify which light comes from which galaxies in images from a survey of millions of galaxies).

Adapting media products and contemporary scientific research for learning and assessment

Physics media products can be used in a variety of ways. Academic research articles can be sourced online and the abstract, findings and conclusions are often suitable for student interpretation.

Teachers should consider the following when accessing media products and contemporary scientific research for classroom use:

• review the media product or information source: check the science, check the suitability for students, check the readability for students, check the availability (how will this medium be shared with students?); in many cases, teachers may need to edit the media product or information source to make the readability and length manageable for students to access.
• decide how to use the article: as an example that illustrates investigation design; as information that students will interpret, assimilate into known information, and explain (for example, a new device, design, product or innovation); as text that requires students to analyse and evaluate research findings; as a comparison with known information (for example, a new method or technique to generate data); or as secondary data for analysis and interpretation.
• guide students to review media communications, checking bias and authenticity while learning how to reference and acknowledge sources.

Teachers may adapt media products and research articles to create assessment tasks (see Suggested approaches to assessment tasks), for example, secondary data analysis, an evaluation of an experimental methodology or method, the explanation of an application of physics in real-world contexts, an infographic, a media analysis or response, or the explanation of a model, theory, device, design or innovation. If assessment tasks are developed collaboratively between schools, then schools must modify the task sufficiently so that the task is unique to each school and each student cohort in a single year in order that authentication risks are minimised. This may be achieved by, for example:

• selecting and adapting different elements of a media product, research article or information source as a basis for the stimulus materials used for the assessment task
• altering the type of assessment task generated from the stimulus material; for example, considering whether structured questions, a flowchart, an oral presentation or a sequence of PowerPoint slides may be appropriate for assessing relevant key knowledge and key science skills.

Student agency

The VCE Physics Study Design provides students with opportunities to develop and demonstrate student agency, particularly in Unit 2 Area of Study 2 where students choose to study an option of personal interest. Student agency represents the ability of students to play a central role in their own development (what they want to learn), practise (how they are learning what they want to learn), and reflection (metacognition or consideration of what they wanted to learn and how they wanted to learn it). A common expression associated with student agency is ‘voice and choice’, which emphasises students as being more active stakeholders in their own learning. Further information about student agency can be accessed at: Amplify.

Problem-based learning

A problem-based learning approach is conducive to linking various scientific concepts and skills to examine science-based issues in society. This approach focuses on open-ended questions or tasks, provides authentic contexts for exploring physics ideas, emphasises student independence and inquiry, and builds capabilities including critical and creative thinking, ethical understanding, and individual and collaborative scientific endeavour.

Scenarios can be developed from actual case studies reported in scientific journals, from local scenarios and issues or from a fictional case study or scenario. A problem-based learning approach can also be used to develop specific key science skills. The key science skills selected should link to relevant physics content.

The following steps are useful when using a problem-based learning approach:

Step 1: Define the question / scenario / problem carefully: what are you trying to find out?

Step 2: Refine the question / explore possible options: use group or class brainstorming to generate ideas.

Step 3: Plan the actual investigation / narrow your choices: may require group or class consensus.

Step 4: Test ideas and obtain further information: use experiments to generate primary data or use a literature review to collate relevant secondary data.

Step 5: Write a conclusion that draws upon discussions / research / experiments.
Problem-based scenarios do not necessarily have a single solution. Class problem-based learning can be used to generate different questions for students to investigate, particularly for experimental investigations.

Examples of two problem-based learning approaches as an inclusion in a teaching and learning program are available below. The first example relates to examining science-based issues in society and supports students in developing their understanding of physics concepts related to the dangers of leaving children in locked in cars on hot days. The second example shows how the key science skill of developing a hypothesis can be structured by addressing the question, ‘Does temperature affect the sound of musical instruments?’.

A problem-based learning environment is conducive to linking scientific concepts to examining science-based issues in society. Scenarios can be developed from actual research studies reported in scientific journals, local scenarios or issues, an imaginary scenario, an interesting physics phenomenon or a fact-based or fictional case study, as in the following example.

A problem-based learning approach can also be used to develop specific science skills. The skills should link to relevant physics content. The following example focuses on the skill of hypothesis formulation.

Socratic seminars

Socratic seminars, also called Socratic circles, are based on Socrates’s belief in the power of asking questions; inquiry is prized over information, and discussion over debate. Socratic seminars are characterised by the inclusion of open-ended questions to inspire thinking. They are structured, dialogic and student-driven discussions with the teachers acting as guides and facilitators rather than as a ‘sage on a stage’. They reflect the highly social nature of learning and align with the work of John Dewey, Lev Vygotsky, Jean Piaget and Paulo Friere. Socratic seminars support student agency and, while there are suggestions in the educational literature as to how to run them in the classroom, teachers may adapt them for their own purposes. An example of the use of a modified Socratic seminar approach to teaching is provided in the extended Detailed example in the Unit 2 Area of Study 2 learning activities.

Questions that draw out the completeness and accuracy of students’ thinking include those that:

• clarify concepts, for example: What does this mean? Can you give an example?
• probe assumptions, for example: What can be assumed? What would happen if…?
• probe rationale, reasons and / or evidence, for example: What evidence is there to support your statement?
• question viewpoints and perspectives, for example: Who benefits from this? Why is it better than or different from…?
• probe implications and consequences, for example: Do these data make sense? What are the consequences f that assumption?
• question the original question, for example: Why is the question important?

In VCE Physics, students are required to identify and explain the physics ideas involved in contemporary societal issues and to use physics ideas to justify a particular stance, solution or response to these issues. This is an important skill for scientists because research into the work of contemporary Australian scientists shows that they need to be able to explain what they know and how they know it. It is also an important skill for non-scientists, since we live in societies in which all citizens should be able to develop an informed and critical perspective on contemporary science-based issues.

What is a socio-scientific issue (SSI)?

A socio-scientific issue (SSI) is a real-world issue that has a basis in science and has a significant impact on society. Socio-scientific issues do not have to involve novel or cutting-edge science and the issue does not have to be highly controversial to be worth investigating.

Socio-scientific issues almost always involve information that is incomplete in some way. This could be because the science is incomplete, but it is more likely because the application of the science to the situation is novel, or not completely reported. It can be because people have different views about an application of science. Some people may see the science as clear and fully resolved, but others may have further questions that may not have straightforward answers.

Socio-scientific issues can be highly emotional, and decisions made about an SSI are rarely, if ever, purely cognitive. When teaching about an SSI it is important that this complexity is acknowledged, and that students are made aware that people, including themselves, may disagree with a decision, a stance, or a solution because they disagree with the values and not because of the science involved. Taking a stance and proposing a solution to an SSI will involve some cost-benefit analysis in which risk interacts with values. It will usually require engaging explicitly with ethical reasoning.

Socio-scientific issues in VCE Physics

It is impossible to deal in depth with every aspect of an SSI. Students should set the scene by briefly mapping a wide range of aspects and then deal in depth with one or two. Both of these are important. The wide-range mapping shows that students are aware of the broad context of the issue or application, while the deep focus shows that they can be precise about the relationship between different aspects of the issue.

While SSIs can be investigated across all Units 1 to 4 in VCE Physics, Unit 2 Area of Study 2 contains 18 options that focus on how physics is involved in applications and issues relevant to everyday life. Students explore the physics related to a selected option and they use this physics to form a stance, opinion or solution to a contemporary societal issue or application. In these options, the central physics principles are well established and are listed against each option in the key knowledge. The goal is that the students use the physics as a basis to analyse and evaluate physics-related societal issues. This means that they should take into account the influence of social, economic, legal and political factors relevant to the selected issue.

Examples of socio-scientific questions across Units 1 to 4 VCE Physics provides suggestions of suitable physics questions that include socio-scientific perspectives.

Studying science through an SSI should develop student agency. For this reason, students should choose a topic and an issue that has meaning for them. Socio-scientific issues are complex because they involve science together with a mix of political, economic, legal and cultural factors and there is usually no single correct answer to any question. It is important that the student be invited to see their understanding as related to the information available at the time and their own values and choices. While the science involved in an SSI is definite, other elements may not be and it is possible that faced with the same information at another time they will make another choice.

Further advice and strategies related to using socio-scientific issues to explore physics concepts can be found at Approaches to teaching science using socio-scientific issues.

Physics in the community

Physics has many applications in local communities and students should be encouraged to make these links. This is especially the case when dealing with Indigenous science, where the guiding principle should be ‘Nothing about us without us’. The primary source of Indigenous knowledge should be its Traditional Custodians. If this is not possible, museums and science centres can provide resources that have been collaboratively and respectfully developed with Australia’s First Nations peoples.

Physics plays a part in many workplaces and careers; for example, Newtonian mechanics is used to understand human movement, the development of prosthetic limbs and to investigate traffic collisions. Nuclear isotopes are used in medicine and in industry. Much of this work is highly local and students should be encouraged to talk to people about how physics informs their work. These interactions need to be managed and appropriately supervised for safety.

Finding the physics in a social issue

Contemporary science is multidisciplinary. Recent research into the work of contemporary scientists tells us that science is often done in multidisciplinary teams and is rarely the work of a single isolated scientist. In these teams, physicists may work alongside medical specialists, engineers, chemists, environmentalists, lawyers, sociologists, philosophers, geographers, physiotherapists, speech pathologists and specialist technicians. Even where the science falls clearly within the discipline of physics, the team producing that knowledge is multidisciplinary: for example, astronomy relies on engineers and technicians who construct and maintain telescopes, ICT specialists who support data analysis and graphic designers who may support visualising the data.

What physicists bring to these teams is a specialist body of knowledge and specific ways of thinking about data production and analysis. Physics allows us to provide a particular type of explanation for how things come to be as they are. For example, physics ideas involving the centre of mass of an extended body can explain the best way to perform a pirouette, do the high jump or build a prosthetic limb; this knowledge becomes useful when it is combined with other specialist knowledge from physiologists, coaches or choreographers. Sometimes the physics is described using different terminology: for example, speech pathologists speak of formants, while a physicist might describe these as resonances of the vocal tract. Sometimes physics provides the enabling technology for other sciences. The physics that underpins the Australian Synchrotron enables imaging for medicine and industry: one of the first images of the Covid-19 coronavirus was produced on this machine and made available to researchers around the world.

In each of the options in Unit 2 and the core areas of study across Units 1 to 4, examples of relevant physics have already been identified as seen in Examples of socio-scientific questions across Units 1 to 4 VCE Physics. However, these are not the only real-life situations in which physics has explanatory power. One of the best ways to find out about links between physics and real life is to ask people to talk about their work and listen with an open mind. Another useful way is to read widely in popular science journals and websites.

Further resources to support the teaching of socio-scientific issues are listed at Teacher resources – SSI issues.

Practical work is a central component of learning and assessment in each unit. It includes a range of activities and is also used for a range of purposes, for example:

• developing observational skills
• introducing and / or consolidating a concept or idea to help students in the process of knowledge construction
• developing practical, manipulative laboratory skills
• developing science inquiry skills to enable students to construct evidence-based arguments
• developing understanding and experience of the nature of science and how scientists work.

Practical activities play an important role in developing 21st century transferrable skills and capabilities, with post-secondary educational institutions and future employers looking for critical thinkers who can problem-solve. Practical activities may also be used to develop assessment tasks such as the production of a scientific report or poster based on logbook records, reflective annotations from a logbook of practical activities, analysis of primary data / results, reporting of the design, building, testing and evaluation of a device, and comparison of two investigation methods. As a guide, teachers should ensure that students undertake at least one practical activity for each sub-heading of key knowledge in each area of study.

A ‘practical activity’ refers to any teaching and learning activity which at some point involves students observing or manipulating the objects and materials they are exploring. The observation or manipulation of objects might take place in a school laboratory but could also occur in out-of-school settings such as the student’s home or in the community. Practical activities are not limited to experiments, as this often relates to the testing of a prior hypothesis. While some practical work is of this form, other examples are not. The scientific methodologies listed on page 13 of the VCE Physics Study Design include those that provide opportunities for a range of practical activities to be undertaken across Units 1 to 4, specifically: classification and identification; experiments; fieldwork; modelling; product, process or system development; and simulations. Examples of practical activities related to the different scientific methodologies are identified in the Teaching and learning activities for Units 1 to 4.

The VCE Physics Study Design does not specify the methodologies, methods or materials required to complete practical activities since each school has a unique resourcing capacity. In addition, different methodologies may be better suited to the key knowledge and relevant key science skills in different areas of study. Teachers are advised to use the flexibility afforded in the study design to decide when students will develop, apply and demonstrate their understanding of each of the scientific investigation methodologies across Units 1 to 4.

Simulations, remote experiments and virtual experiments may be used as the basis for experiments where physical resources (for example, equipment, facilities or access to appropriate sites) are limited. Students may also be provided with sample experimental data, where physical resources are not available, so that they may represent the data in chart and / or graph form, analyse the results and report their conclusions.

Fieldwork provides opportunities outside the laboratory for students to learn important skills including research design, data generation and recording. Practical work related to astronomy, projectile motion and GPS applications support learning in the classroom and in the laboratory. Field sketches or photographs can be used to provide information about the context of a practical activity undertaken outside the classroom.

Interviews and questionnaires are also relevant to Physics as fieldwork, particularly in gauging views about physics-related socio-scientific issues. Questionnaires can be structured in a way that makes the data readily presented in graphical form – typically bar charts or column graphs – whereas the use of open-ended questions in interviews enables more detail to be elicited. Students should be respectful of others’ views and should consider the sensitivity of some topics prior to using questionnaires or conducting interviews. Ethical practices in science include that any research involving human subjects, including questionnaires and interviews, may be conducted only with the informed consent of the subjects, even if this condition limits some kinds of potentially important research or influences the results. Students are therefore advised to inform possible participants as to the nature of the questions that will be asked, seek permission to continue with the questionnaire or interview, and advise participants that they may withdraw at any time.

Applications of physics concepts can be illustrated through excursions such as visits to scientific, medical, commercial or industrial sites; for example, The Australian Synchrotron or the radiology department of a hospital. All health and safety regulations must be followed, and teachers are advised to contact sites prior to arrival to ascertain possible risks and to review risk management procedures.

To collaborate respectfully and meaningfully with Aboriginal and Torres Strait Islander communities, local protocols and agreements are required to determine how Koorie knowledge and data can be accessed, shared and used. The study design provides guidance and web links to relevant resources related to protocols. The Traditional Owners for any location can be identified using the maps in Victoria and in Australian locations . 

Teachers are encouraged to include relevant Aboriginal and Torres Strait Islander knowledge and perspectives in the design and delivery of teaching and learning programs related to VCE Physics. VAEAI is the peak Koorie community organisation for education and training in Victoria. VAEAI has produced the Protocols for Koorie Education in Victorian schools, to support teachers and students to learn about local, regional, state and national and international Indigenous perspectives.

The VCAA has prepared on-demand video recordings for VCE teachers and leaders as part of the Aboriginal and Torres Strait Islander Perspectives in the VCE webinar program held in 2023 which was presented with the Victorian Aboriginal Education Association Inc. (VAEAI) and the Department of Education (DE) Koorie Outcomes Division.

Lisa Daly from Cultural Minds provides some useful advice when considering how to include Aboriginal and Torres Strait Islander perspectives in VCE Physics: ‘…It is important to understand there is a distinct difference between teaching Aboriginal culture and teaching about Aboriginal culture. It is not appropriate for a non-Aboriginal person to teach Aboriginal culture, that is the traditional or sacred knowledge and systems belonging to Aboriginal people. For these kinds of teaching and learning experiences it is essential to consult and collaborate with members of your local Aboriginal or Torres Strait Islander community. It is appropriate however, for a non-Aboriginal person to teach about Indigenous Australia, its history and its people in much the same way as a teacher of non-German heritage might teach about Germany, its history and its people… As teachers, the onus is on us to learn about Indigenous Australia, in just the same way we inform ourselves about any other subject we teach…’

VAEAI Cultural Understanding and Safety Training (CUST) is a useful professional learning activity for teachers to undertake when considering how they may best include Aboriginal and Torres Strait Islander perspectives in VCE Physics.

Other resources when considering Aboriginal and Torres Strait Islander perspectives:

Aboriginal Victoria, Culture Victoria, Museums Victoria, and Forest Fire Management Victoria.

There will also be Aboriginal and Torres Straits Islander knowledge, culture and perspectives that are appropriate to include and consider from other states in terms of a national Australian context, or other Indigenous perspectives from other countries that are appropriate from an international context.

Unit 2 Option 2.15: ‘How can physics explain traditional artefacts, knowledge and techniques?’ on page 44 of the study design provides opportunities for students to apply physics concepts to explain the operation, behaviour or understanding of a chosen artefact, knowledge or technique used by Aboriginal and Torres Strait Islander peoples.

Teachers may also choose to include aspects of Aboriginal and Torres Straits Islander knowledge, culture and perspectives in the core units of the study to illustrate physics principles; for example, analysing the forces in the operation of a woomera as an extension of the human arm in Unit 3 Area of Study 1.

The set of eighteen options on pages 31–47 of the study design have been developed to support student agency and voice. Approaches such as ‘flipped classrooms’ and the use of Socratic seminars may be used to scaffold student independent learning. The overarching question for this area of study, ‘How does physics inform contemporary issues and applications in society?’ and the common set of key knowledge points for all options listed under the sub-heading ‘Communicating physics’ can be used as the basis for determining the expected outputs and assessments for students that will be equitable given that the contexts will vary. The key knowledge sub-heading ‘The physics of…’ directs students to the concepts that are relevant to each option to guide their individual research and to help them develop content for the determined outputs and assessments. All research references should be recorded in students’ logbooks.

Content included in the options may be used to support learning in the core areas of study. Making these connections will also introduce students to the scope of the options so that they can make an informed choice about which option they will elect to study. Examples of how content from the options may be integrated into the core areas of study as contextualised examples to illustrate physics principles can be found at Integrating Unit 2 options as applications across Units 1 and 2.

When developing teaching and learning programs, teachers must consider:

• duty of care in relation to health and safety of students in practical work, investigations and excursions, including in the laboratory and when undertaking fieldwork
• legislative compliance (for example, electrical safety and copyright)
• sensitivity to cultural differences and personal beliefs (for example, discussions related to medical issues)
• adherence to community standards and ethical guidelines (for example, maintaining confidentiality of personal details)
• respect for persons and differences in opinions; sensitivity to student views on the use of living things in research (for example, in considering physics-related socio-scientific issues).

The VCE Physics study provides students with the opportunity to engage in a range of learning activities. In addition to demonstrating their understanding and mastery of the content and skills specific to the study, students may also develop employability skills through their learning activities.

The nationally agreed employability skills* are: Communication; Planning and organising; Teamwork; Problem solving; Self-management; Initiative and enterprise; Technology; and Learning.

*The employability skills are derived from the Employability Skills Framework (Employability Skills for the Future, 2002), developed by the Australian Chamber of Commerce and Industry and the Business Council of Australia, and published by the (former) Commonwealth Department of Education, Science and Training.

Curriculum-framing questions in the study design

Scientific inquiry involves students asking or responding to a question by selecting an appropriate investigation methodology and developing a method to generate primary and / or secondary data, and then reporting findings in response to the question. It is an approach that enables students to discover and learn through their own or guided explorations in response to scientific questions. The range of scientific investigation methodologies appropriate for VCE Physics is listed on page 13 of the study design.

The VCE PhysicsStudy Design is structured as a series of curriculum-framing questions that reflect the inquiry nature of the discipline. These questions are open-ended to enable students to engage in critical and creative thinking about the physics concepts identified in the key knowledge and associated key science skills, and to encourage students to ask their own questions about what they are learning. In responding to these questions, students demonstrate their own conceptual links and the relevance of different concepts to practical applications.
Using a scientific inquiry approach enables students to:

• engage with science-based questions
• prioritise evidence in responding to questions
• formulate explanations from evidence
• connect explanations to scientific knowledge
• communicate and justify science-based explanations of concepts and phenomena.

Teachers are advised to use the flexibility provided by the structure of the study design in the choice of contexts, both local and global, and applications for enabling students to work scientifically and answer questions. Opportunities range from the entire class studying a particular context or application chosen by the teacher or agreed to by the class, through to students nominating their own choice of scenarios, research, case studies, fieldwork activities or ethical issues.

At the end of a unit or on completion of an outcome, students should be able to respond to the relevant curriculum framework questions. Teachers may consider using these as the basis for an assessment task.

Levels of student independence in scientific inquiry

Scientific inquiry can be scaffolded to support students in developing key science skills. The level of scaffolding selected will depend on factors such as students’ prior skills and the level of complexity of the investigation and / or the methodology and / or the method.

Five levels of scaffolding of scientific inquiry can be used:

• A confirmation / prescription inquiry involves students confirming a principle through an activity when the results are known in advance; students are provided with the question, method and results, and are required to confirm that the results are correct.
• In a structured inquiry, students investigate a teacher-presented question through a prescribed procedure; students generate an explanation supported by the evidence they have generated or collated.
• In guided inquiry the teacher chooses the question for investigation; students work in one large group or several small groups to work with the teacher to decide how to proceed with the investigation. This type of inquiry facilitates the teaching of specific skills needed for future open-inquiry investigations. The solution to the guided inquiry should not be predictable.
• A coupledinquiry combines a guided inquiry investigation with an open inquiry investigation: the teacher chooses an initial question to investigate as a guided inquiry and students then build on the guided inquiry to develop an extension or linked investigation in a more student-centred open inquiry approach.
• An open inquiry most closely mirrors scientists' actual work and is a student-centred approach that begins with a student's question, followed by the student (or groups of students) designing and conducting an investigation or experiment and communicating results.

Investigations related to a particular topic may range from being a confirmation / prescription type inquiry through to an open inquiry, dependent on student experience. Teachers may consider organising students into groups according to their level of experience so that targeted support can be provided to build students’ skills when undertaking and designing investigations.

The principles of the scientific method through fair testing and the design of controlled experiments are important in science but may not always enable students to understand scientific ideas or concepts, answer their questions or appreciate how scientists work and the nature of science. For VCE Physics, eight different scientific investigation methodologies to generate primary and / or secondary data may be used and have been outlined on page 13 of the study design.

Common to different scientific investigation methodologies are three key aspects that are central to the study design's inquiry focus:

• asking questions
• testing ideas
• using evidence.

Teachers should ensure that students are provided with opportunities to undertake each of the eight scientific investigation methodologies listed on page 13 of the study design across Units 1 to 4 so that students can evaluate when and why it is appropriate to use some and not others. Students should select and justify a selected methodology, and then determine an appropriate method and / or technique that will be used, in response to an investigation question or issue. The choice of scientific investigation methodology will be determined by the question under investigation. There should be congruence between the question under investigation and the chosen methodology. The selected method and associated data generation and collection techniques should also be congruent with the chosen methodology.

Some methodologies may be more widely used in VCE Physics than others, particularly experiments, modelling and simulations, and will depend on the nature of the investigation.

For many investigation methodologies, an investigation question may not lend itself to having an accompanying hypothesis; in such cases students should work directly with their investigation questions.

Examples of teaching and learning activities that use different scientific methodologies have been provided in Examples of scientific methodologies applicable in VCE Physics. Further examples for each unit and area of study can be found in the Teaching and learning activities. Information related to the use of variables in physics investigations can be found at Defining variables.

Some scientific practical investigations will be student-designed and / or adapted by students, depending on the outcome and the level of student experience in undertaking practical work. Teachers must approve all student practical investigations to be undertaken. Not all planned student investigations can proceed due to issues including safety, equipment availability, time constraints and / or management of large student numbers.

Due to the potential scope of scientific investigations, students must be practical and realistic when deciding on investigation topics. Teachers need to be equally pragmatic when counselling students about their choice of investigation topic and when guiding the student in the formulation of the investigation question. Appropriate teacher intervention not only minimises risks but also serves as important feedback for students. Schools should have in place approval mechanisms, either through ethics committees or approval authorities within the school, to ensure that students undertake appropriate research.

Scientific investigation phases

Regardless of the scientific investigation methodology chosen, planning and conducting a scientific investigation involves six distinct but interrelated phases. The following diagram shows the relationships between each phase in designing and undertaking scientific investigations:

Diagram 3

Image description

1.  Investigation exploration phase – initiating inquiry

The selection of a suitable scientific inquiry topic, and the subsequent construction of a question or hypothesis for investigation, may be initiated in a number of ways including:

• from brainstorming
• through direct observation of, and curiosity about, an object, an event, phenomenon, a practical problem or a technological development
• as a result of anomalous or surprising investigation results
• as an extension of a previous inquiry
• from analysis of qualitative and / or quantitative data
• from research involving secondary data
• teachers providing a generic question that is refined by students
• teachers scaffolding the development of an appropriate testable hypothesis that students can adapt and investigate, where the level of scaffolding will be dependent on student experience in scientific inquiry.

In selecting a question or hypothesis for investigation, students may undertake relevant background reading or refer to previous investigations. Students should reference sources and provide appropriate acknowledgments.

There is no mandated VCE style for writing a hypothesis, although many students are familiar with an ‘If…then…because…’ style of hypothesis formulation.

Teachers should ensure that students do not proceed with an investigation question or hypothesis that is not testable or is impractical to investigate in terms of time or resources.

2.  Planning phase – methodology and method

Prior to undertaking an investigation, students should produce a plan in their logbooks that:

• outlines their reasons and interest in undertaking the investigation
• defines the physics concepts involved
• identifies the methodology
• outlines the methods / techniques that will be used, including an investigation procedure and risk management for the investigation  
• lists the materials and equipment required
• identifies and suggests how potential safety risks and anticipated problems can be managed
• outlines any ethical issues.

Students may also make predictions about investigation outcomes based on their existing knowledge and prior experiences.

Depending on the type of scientific inquiry, teachers may choose to model and / or guide students to complete any of the above aspects of investigation planning. Teachers should ensure that proposed investigations have an appropriate methodology and method. In some cases, modifications to the investigation plan may be required, or students may be directed to reconsider their original investigation question or hypothesis.

3.  Investigation phase – testing ideas

In the investigation, students will generate primary or collate secondary qualitative and / or quantitative data as evidence. Data can be derived from a number of sources including observations, laboratory experimentation, fieldwork, simulations, trials of designed and constructed artefacts, and local and / or global databases. During the investigation phase students should note any difficulties or problems encountered in generating and / or collating data. Data that is relevant to the investigation should be recorded in a form that enables subsequent interpretation, analysis and evaluation.

Depending on the type of scientific inquiry, teachers may choose to model and / or guide students to generate primary and / or collate secondary qualitative and / or quantitative data as evidence. In some cases, insufficient – or no – data may be obtained by students. In physics, this is often due to method errors (for example, connecting a multimeter incorrectly or not keeping track of the different springs used in different experiments) or it may be due to systematic errors, such as not checking / testing / calibrating a data logger or not zeroing a scale / balance when measuring the mass of objects used in a motion experiment. Students may be directed back to revise their investigation plan or, if time does not permit, they may access other student data, or secondary data, relevant to their investigation.

4.  Processing phase – using evidence

Analysis, interpretation and evaluation of investigation data may identify evidence of patterns, trends or relationships and may subsequently lead to an explanation of the physics question being investigated. For VCE Physics, the analysis of experimental data requires consideration of:

• accuracy, precision, repeatability, reproducibility, resolution, true value, and validity of measurements and experiments (see page 20 of the study design under ‘Measurement terms’)
• errors, uncertainty, significant figures, and the treatment of outliers (see page 22 of the study design under ‘Measurement errors, uncertainty, significant figures and outliers’).

Students consider the data generated and / or collated and make inferences from the data, report mistakes or problems encountered and how they were managed, and use evidence to answer the investigation question. They consider how appropriate their data is in a given context, evaluate the validity of the data and make reference to its repeatability and / or reproducibility. Uncertainties in measurements, including random and / or systematic errors and the treatment of any outliers in a set of data, should be identified and explained.

For a scientific investigation where a hypothesis has been formulated, interpretation of the evidence will either support the hypothesis or refute it.

For investigations that include a prediction, students should comment on how their prediction compared with their results and attempt to account for differences.

In reaching a conclusion to an investigation question, students should identify any judgments and decisions that are not based on the evidence alone but involve broader environmental, social, political, economic and / or ethical factors.

5.  Reporting phase – sharing findings

When recording data and reporting findings, students should use correct scientific language and conventions, including the use of technical terms, standard notation and SI units.

The initial phases of the investigation (question construction, planning, investigation. and analysis and evaluation) are recorded in the student logbook while the report of the investigation can take various forms including a written scientific report, a scientific poster or an oral or a multimodal presentation of the investigation findings.

Students should also be mindful of the audience for their communication. In general, students should write to an audience of their class peers.

6.  Further investigation phase – new directions

While some investigations may provide answers to questions of interest, others may lead the student to revising their original hypothesis or developing a new one. Almost all scientific investigations can lead to the generation of new questions that may be investigated as an extension of the original question or as a novel question that may require different methodologies, methods and / or techniques to be applied. The student-designed investigations in Unit 2 Area of Study 3 and Unit 4 Area of Study 2 may be developed or adapted from previously completed investigations (coupled investigations).

While the maintenance of a logbook is common scientific practice in recording primary data, the way that logbooks are used for VCE Physics purposes has been extended to include notetaking by students related to the collation of secondary data as well as supporting teachers to authenticate and assess student work. 

The presentation format of the logbook is a school decision, and no specific format is prescribed. Its purposes may include:

• providing a basis for further learning; for example, contributing to class discussions about demonstrations, activities or practical work
• reporting on an experiment or activity
• responding to questions in a practical worksheet or problem-solving exercise
• writing up an experiment as a formal report or as the basis of a scientific poster
• planning for presentations such as the explanation of a physics device or phenomenon.

Data contained within a student’s logbook may be qualitative and / or quantitative and may include the results of guided activities or investigations; planning notes for experiments; results of student-designed activities or investigations; personal reflections made during or at the conclusion of demonstrations, activities or investigations; simple observations made in short class activities; links to spreadsheet calculations and other student digital records and presentations; notes and electronic or other images taken on excursions; database extracts; web-based investigations and research, including online communications and results of simulations; surveys; interviews; and notes of any additional or supplementary work completed outside class.

The logbook may be maintained in hard copy or electronic format. For many schools, it may be easier to require that students maintain a hardcopy logbook to avoid falsification and / or alteration of results. All logbook entries must be dated and in chronological order. Investigation partners, expert advice and assistance and secondary data sources must be acknowledged and / or referenced in the logbook.

For Unit 4, Area of Study 2, the student’s logbook entries may be assessed as well as their scientific poster.

For more information and advice regarding the assessment of Unit 4, Outcome 2 see Suggested approaches for developing assessment tasks.

Scientific posters are widely used in academia, research and in the general scientific community as a visual means of communicating the outcomes of scientific investigations. They are not designed to simply replicate a scientific report in that they provide a different means by which science information is communicated, particularly to peers and the school community. Teachers may elect to include the requirement for an oral presentation to accompany a scientific poster. The use of QR codes to link poster sections to a complete practical report or to sections of the logbook may be used by some schools but is not compulsory. If QR codes are used in the Unit 4 Area of Study 2 scientific poster, the words do not count as part of the 600-word limit.

Design principles for scientific posters

Key design principles for effective scientific poster communication for the purposes of VCE Physics include:

• Logical sequencing and easy identification on the poster of the hypothesis or question, aim and conclusion and other key parts of the investigation.
• Inclusion of only the essential details for conveying what was done in the investigation and what was discovered (for example, only the key aspects of an experimental procedure should be outlined).
• Use of relevant visual aids (for example, tables, photographs, diagrams and graphs) to reduce the amount of text, thereby avoiding overcrowding of the poster.
• Use of font, font size and colours that will be easily read by all those viewing the poster (note that red and green are difficult to read by many people).
• Careful editing of text – terminology and spelling should be checked; wording should be simplified; acronyms should be defined; and complexity should be reduced (for example, phrases or bullet points, rather than sentences, should be used). A test is that others with little or no background in the area under investigation should be able to understand the language and identify the key points of the investigation.
• Clear labelling of all images (for example, diagrams or photographs of the experimental set-up or results).
• Graphs drawn with clear, relevant scales, grids, labels and annotations.
• Editing of graphs derived directly from spreadsheet programs so that graphs do not have coloured backgrounds, grid lines, or boxes that distract from the poster information.
• Axis labels formatted in sentence case (Not in Title Case and NOT IN ALL CAPS).
• Calculations presented in a clear, non-repetitive manner (for example, one sample calculation can be shown and then the results of similar calculations can be displayed in a table); appropriate units must be shown.
• All references stated and appropriate acknowledgments provided.

Scientific poster sections

Scientific poster sections, specifically the communication statement reporting the key finding of the investigation as a one-sentence summary, title, introduction, methodology and methods, results, discussion, conclusions, references and acknowledgments, are mandated for the scientific poster that is constructed as part of the assessment for Unit 4 Outcome 2. Within the mandated sections, some tailoring of organisational elements is optional.

The centrally placed one-sentence statement of student investigation results in the scientific poster for Unit 4 Outcome 2 emphasises the importance of clear, succinct scientific communication to the wider community, and requires that students carefully consider why they had undertaken their selected investigation and how the major investigation finding can be reported. A single key graphic or photograph, or sequence of illustrations or photographs, relevant to the investigation results could be added to this central panel for visual impact. 

Scientific poster templates available in the public domain may be used provided that the mandated poster sections are included. The use of a template can help to minimise many common communication faults by keeping column alignments logical, including mandated sub-headings that provide clear cues as to how readers should travel through poster elements, and maintaining sufficient 'white space' so that clutter is reduced.

There is no mandated VCAA style for the use of person or voice in writing a scientific poster, since the scientific community has not reached a consensus about which style it prefers. Increasingly, using first person (rather than third person) and active (rather than passive) voice is acceptable in scientific reports and posters, because arguably this style of writing conveys information more clearly and concisely.

However, this choice of person and voice brings two scientific values into conflict – objectivity versus clarity – which may account for the different viewpoints in the scientific community. Use of tense is dependent on the section of the report: when describing something that has already happened (for example, the investigation procedure) then past tense is used, as in 'The aim of the experiment was to...'; when describing something that still exists (for example, the report, theory and permanent equipment) then the present tense is used, as in 'The purpose of this report is to...', 'Newton’s second law states that...' and ‘A cathode ray oscilloscope can be used to...'

The 600-word limit for the scientific poster requires that students carefully consider what should be included to ensure effective science communication. Teachers may assess some components of the investigation through logbook entries, particularly some of the background information, data manipulation and discussion of results. Poster title, student name / identification number, tables, graphs, flowcharts, figure captions, references and acknowledgements are not included in the poster word count.

Further consideration of the poster format in the VCE Physics Study Design 2023–2027 can be found at: How to create a better research poster in less time (#betterposter Generation 1) - YouTube

Further advice about assessment of the scientific poster can be found in the Suggested approaches for developing assessment tasks section of this resource.

Scientific inquiry in physics requires students to apply numeracy skills so that they can make and record observations, organise and analyse data, and interpret trends and relationships.

In processing, evaluating and discussing their own and others’ data it is expected that VCE Physics students will be able to:

• distinguish between qualitative and quantitative data, and between primary and secondary data
• record data in a suitable table, with appropriate units in the row or column headings
• use a calculator for addition, subtraction, multiplication and division, and to calculate squares (x²), square roots (√x), and reciprocals (1 / x)
• perform calculations involving means, decimals, fractions, percentages, ratios, approximations and reciprocals
• perform manipulations with trigonometric functions
• interpret and transpose mathematical formulas in order to calculate and predict values 
• convert between units
• select and use the most appropriate units for recording data and the results of calculations
• use standard notation
• use direct and inverse proportion
• solve simple algebraic equations
• plot graphs (with suitable scales and axes) including two variables that show linear and non-linear relationships
• interpret graphs, including the significance of gradients, changes in gradients, intercepts and areas under graphs
• draw lines (either curves or linear) of best fit on a scatter plot graph
• construct linearised graphs taking into account uncertainty bars (when known) and identify the significance of the gradient
• construct and interpret diagrammatic representations of data, including pie charts, line graphs, scatter graphs and bar charts, both using technology and drawn by hand using a pencil with a 2B lead.

Teachers and students should refer to the definitions of measurement terms in the VCE Physics Study Design on pages 20–22. Students need to see these terms used in practice, have a variety of experiences themselves, and have opportunities for feedback about the use of these terms.

Teachers should be aware that confusion has occurred and is likely to occur when:

• a term has an everyday meaning which is different from the specific meaning in measurement, for example: ‘accuracy’ and ‘uncertainty’
• the context has not been clearly defined, for example: ‘Is precision improved by taking more readings?’ could be understood in two ways. See ‘Precision’ below.

Examples and discussions below largely deal with known misunderstandings.

The concept of uncertainty is central in measurement. The internationally agreed approach is set out in the Guide to the Expression of Uncertainty in Measurement first released in 1995.Commonly abbreviated as the GUM, it applies across all fields involving measurement and sets out a rigorous treatment far beyond senior secondary needs. See GUM htlm online. (The JCGM is responsible for both the GUM and VIM.)

Uncertainty quantifies the interval in which the true value is expected to lie. For instance, students should recognise that a measurement result given as 5.00 ± 0.01 mm, has an uncertainty of 0.01 mm. Note that the value of the uncertainty is strictly the absolute value, no ‘±’ sign. Students are not expected to be aware of the choices made in expressing uncertainty, such as the standard deviation or a 95% coverage (confidence interval).

Estimation of uncertainty is complex; hence, VCE students are not required to treat uncertainties quantitatively. However, simple numerical values are given in a few examples in order to illustrate a concept. Students should be able to recognise a numerical value of uncertainty when clearly described in an example.

‘Uncertainty’ has an everyday meaning of ‘not being sure’ or ‘doubt’. Distinguishing everyday usage from its specific meaning in measurement is essential. The measurement context should always be clear; for example, ‘the uncertainty in the temperature of the water’. When ‘uncertainty’ is meant to have its general meaning, this should be explicitly stated. Asking ‘What is the meaning of uncertainty?’ is ambiguous.

Since ‘true value’ is unknowable, some may consider that it is unnecessary as a concept. However, true value is used to define other key terms, such as ‘error’. If ‘true value’ is replaced with a term such as ‘expected’ or ‘reference value’, the terms depending on ‘true value’ will have different meanings. Furthermore, if a measurement result is the same as that expected value, then the error in the measurement is zero, but that is a false conclusion.

Research has shown that students commonly think of the true value as being a single value. In reality, the measured quantity may span a range of values due to variation in the object of the measurement rather than arising from the measurement process. A simple example is the diameter of a wire: the wire is not a perfect cylinder but has variations from production and handling; hence, error-less measurements of the ‘diameter’ at different points will vary. Similarly, there is no single value for the ‘temperature of this room’.

There are three pitfalls with the use of the term ‘accuracy’. The first misunderstanding occurs when ‘accuracy’ is used as a substitute for ‘uncertainty’. For example, ‘DC Voltage: accuracy ±1.2%’ in the specifications for a medium-priced popular brand multimeter. Even professional science and technology magazines may write ‘an accuracy of so many parts per million’. We can’t change or avoid such usage but we can model the correct usage, and perhaps have students set out to find flawed examples.

Second, students need to change their mindset; rather than asking ‘Is my result sufficiently accurate?’, the focus should be on uncertainty. Consider this example. Students use a method to measure a quantity for which the true value is (hypothetically) known to be 5.00 ± 0.02 units. Student A gets 5.1 units, student B gets 5.0 units, both using the same method, sample and good quality instrument. B claims ‘My result is so accurate!’ But B’s value could be just the result of chance. What is more important is the quality of A and B’s measurements; this is indicated by the uncertainty in their measurement result. Since their method, sample and instruments are the same, then the uncertainty estimate should be the same. (In this example, the quality of their results is the same unless a mistake had been made.)

Similarly, the meter specification mentioned above should state ‘uncertainty in the DC voltage scales is …’.

The third pitfall is giving a numerical value for accuracy. A measurement result is considered to be accurate if it is judged to be close to the true value of the quantity being measured. Since the actual true value cannot be known, it is not possible to quantify how close a measurement result is. The term ‘uncertainty’ should be used, instead.

It is allowable to claim that one method / instrument is more accurate than another when there is evidence, such as from calibration or comparison with a more accurate method / instrument.

The study design requires students to be able to recognise causes of uncertainty. It is not sufficient to say ‘systematic’ or ‘random’ errors, since these are adjectives which simply refer to types of errors. For any particular measurement, there will be specific causes of errors. Teachers are advised that students cannot be expected to recognise all causes of errors in measurements they carry out, let alone in situations they have not experienced.

Causes of errors may arise in the measuring instrument, in the object or quantity itself, or from the method used. For many instruments used in school investigations there is likely to be either minimal, or no, information on systematic errors. At best, ‘accuracy’ might serve as an estimate of uncertainty. It is possible that in measurements of current and voltage in a circuit, there is no evidence of random errors when the meter shows the same value each time.

Refer to Examples of causes of uncertainty as an illustration of factors that may be considered in discussing causes of uncertainty.

The effect of random errors can be identified, and reduced, by repeated measurements.

Systematic causes can be identified by undertaking further investigations. It may also happen that what looked like random errors actually has a systematic cause. A simple example is measuring the diameter of a wire using a micrometer gauge, such as in an investigation of how resistance depends on length and diameter. Measurements may show that the diameter is not exactly constant; rather, it varies depending on where along the wire and in which direction across the wire the micrometer is placed. These variations may be caused by manufacture or subsequent handling. Depending on the purpose of the investigation, it might be important to check if the wire gets thinner from one end to the other, and if the wire is consistently elliptical in cross-section rather than circular; each indicates a systematic behaviour. If the method allowed the wire to rotate as the micrometer jaws were being closed, then it is likely that all the measurements will be of the shorter axis of the ellipse. This would result in a systematic error if the investigation required the cross-sectional area. Further consideration could be given to how the micrometer is used, and whether it has sufficient resolution for the wire being measured.

In summary, improving uncertainties always involves further measurements including refinements to the method. In the case of an instrument’s specifications or calibration, the underpinning measurements are done by others.

The study design notes the importance of repeating measurements to reduce the effect of random errors. Sometimes the random errors might be small, or not perceived due to limited instrument resolution. Unless there is a need to accurately characterise a distribution of results, which is beyond the scope of the study design, then four to six measurements should be sufficient.

The more measurements we take, the closer their mean will be to the true value or true mean (‘population mean’ in statistics). Consider a set of four individual measurements – does this give a reliable mean value? This can be checked by repeating the measurement, obtaining further sets each of four measurements, and a mean for each of those sets. These means will usually not be the same as each other but will cluster around the true value. There is also a mean of all the data which will be the best estimate available. If it were critical to have a reliable estimate of the random error uncertainty in order to decide how many individual readings should be made, then this can be done with basic statistics.

Precision appears to be an easy concept, but issues may arise. First, it is meaningless to refer to the precision of a single measured value. The VIM defines precision as the closeness of agreement from replicate measurements; several measured values are needed.

Second, while VIM allows for precision to be quantified, this is not required for VCE Physics since students do not have the required statistical concepts.

Third, the intended ‘measurement quantity values’ must be clear. The VIM definition of precision refers to both ‘indications’ and ‘measured quantity values’. ‘Indications’ broadly means the reading or meter pointer position, etc., which can apply to the individual ‘readings’. This idea is conveyed by diagrams marking the position of several individual readings. So, if the investigator only wants to comment on the closeness of agreement of individual readings or indications, this must be stated explicitly.

The wider term ‘measurement quantity values’ most generally applies to the ‘measurement result’ from several readings, and is usually represented by the mean. The ‘mean’ (and accompanying uncertainty) is the measurement result presented in the discussion, conclusion or application. Individual values have played their role once the mean and scatter have been determined. If ‘precision of the overall measurement result’ is intended, this should be clearly stated. It is entirely correct to claim that ‘repeating measurements improves the precision of the mean measurement result’. What is at stake is the closeness of agreement when the whole measurement (a set of individual values) is replicated and new means, that is, new measurement results, are obtained. These means will be closer to each other than the original individual results are to each other (as described in the previous section).

In conclusion, ‘repeating measurements improves precision’ is incomplete as there are two interpretations. Repeating individual measurements does not remove random errors. However, repeating the whole measurement does improve the precision of the measurement result (understood as the mean).  

The study design, p.21, goes no further than saying ‘The spread of individual measurement values provides an indication of the (final) measurement’s precision.’ This avoids getting into the details of exactly what ‘precision’ is being applied to.

In some cases, it is possible to compare the results obtained from an investigation with an expected result. Examples include the value of free-fall acceleration g since values of g are known at measuring stations across Australia, or a quantity that has been measured with a suitably accurate instrument or method.

It is important to include the uncertainty estimate given by the source of that value. It can be said that there is agreement between a measurement result and the expected value when there is an overlap between the interval ‘mean ± uncertainty’ of your result and the ‘mean ± uncertainty’ given for the reference / comparison quantity. If there is a small discrepancy the reason may be that the uncertainty was underestimated in the investigation.

Teachers should be aware that fundamental constants such as e, c, G, h, etc. are now defined quantities with no experimental uncertainty. Standards are now tied to physically measurable characteristics such as the frequency of a particular atomic transition. Thought should be given to the stated purpose of any experiment which seeks to measure e / m for an electron, G, or h / e. Such experiments test the accuracy of quantities measured such as potential differences, distances, frequency of light or mass, or the inherent resolution of investigation.

A second common situation in VCE Physics is when a relation is expected between a dependent variable and an independent variable, commonly a linear relationship. The measured values have an associated uncertainty, which can be shown on the graph as an uncertainty bar at each data point. If a straight line can be produced which passes through, or sufficiently close to, the uncertainty bar region for all points then the linear relationship is confirmed, within the uncertainties of the experiment.

This does require a reliable estimate of the uncertainty of the measurements involved which generally cannot be done for the systematic error component. For the purposes of helping students understand what is involved, a reasonable estimate might be suggested to them, such as an uncertainty for DC voltages on a particular digital voltmeter based on the meter’s specifications. There may be other considerations, such as in the photoelectric effect where there is an uncertainty in determining exactly when the photocurrent has dropped to zero, as well as what actual frequencies are in the light used.

There may be instances where uncertainty due to random errors can be estimated but there is no reliable way to include systematic error effects. The graph could show uncertainty bars with a clear label or caption that these are due to random errors only. A systematic effect might be detected if, for instance, the plot of the experimental data followed a distinct curve rather than the expected straight-line relationship.

When planning an experiment involving a straight-line graph, the question arises as to how many data points. A decision needs to be made of how many times a measurement is repeated at a particular value of the independent variable. For the purpose of fitting data points to a straight line there is no advantage in making multiple measurements at a single value of the independent variable. For example, compare (a) taking four measurements at four different independent variable values with (b) a single measurement at each of 16 independent variable values. There is a slight benefit in (a) as outlined below, but there will be a better coverage of the overall range from (b). 

Taking a single measurement at many points, as in approach (b), still shows the effect of random errors which will be evident from closeness of data points to the line of best fit. This is true whether the line is drawn by eye or by statistics (regression or least-squares). The quality of the fit depends on the total number of measurements. Having more points spread across the range makes it easier to detect a discontinuity in the slope or a step change in the dependent variable.

Taking several measurements at one value of the independent variable, as in approach (a), has a marginal benefit in immediately indicating the extent of random errors. It is sensible to use both approaches. If for example there was time to take 15 readings, one may decide to take a total of three or four measurements at one value of the independent variable in the lower half of its range, and again in the higher half of the range. This will give a rough estimate of the uncertainty due to random errors and hence allow the size of a suitable ‘random error uncertainty’ bar. There would be single measurements taken at the remaining seven to nine points. There is no practical benefit in trying to better estimate the effect of random errors when the investigator has no or little knowledge of the systematic errors.