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How GAT relates to school-based and external assessments 


School-based assessment and the GAT

The VCAA applies statistical moderation procedures to all school-based assessments to even out the differences in marking standards that may occur from school to school. This is to ensure that the final results are comparable across the state and are fair to all students.

The statistical moderation process compares the level and spread of each school’s assessments of its students in each study with the level and spread of the same students’ scores in the external assessments, and adjusts the school scores if necessary.

In some studies, statistical moderation uses students’ GAT scores as well as their scores for external assessments. This is done where it gives a better match with schools’ school-based assessments throughout the State. The external assessment scores will always have the major influence in the statistical moderation calculations.

There are two key principles in whether and how the GAT is used.

  1. The GAT components are only used if they make the moderation process more reliable in the sense that the external scores are a better predictor using the GAT scores than without them. The statistic R-square is used to measure the increase in reliability.
  2. When used, the GAT components must not exert too much influence on study scores. A variety of tests are performed to determine the influence of the GAT, of which one test is that no more than 5% of study scores should vary by more than 2. To achieve this, the influence of the GAT is kept to the minimum optimal level.

The decision on whether to use the GAT is made separately for each school-based assessment.

More information about statistical moderation can be found in statistical moderation.


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External assessment and the GAT

The VCE external assessment marking process is rigorous, carefully and expertly conducted, and designed to be fair to all students. VCE external assessment will be marked twice, by two different assessors. Each assessment is completed separately and each assessor does not know the marks given by the other assessor. If there is insufficient agreement between their marks, the paper is assessed by a third assessor.

If a student’s score for an external assessment is significantly different from the score predicted by the GAT, school indicative grades and the scores for any other external assessment in the same study, their assessment will be assessed again by the Chief Assessor. See the Anomalous Examination Grades page for more information.

A student’s score may go up or stay the same, but it will not go down as a result of this final check.

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Derived Examination Scores and the GAT

A student whose performance on an examination is affected by the onset of illness, accident or personal trauma may apply for a Derived Examination Score.

All applications for a Derived Examination Score are assessed by a trained, external panel. If an application is approved, a student’s GAT scores will be used in the calculation of the Derived Examination Score.

Additional information on the Derived Examination Score process can be found within Special Provision.