A percentage at one school is not the same at every school
Schools choose assessment tasks and mark them. A 90% on one task may represent different achievement from 90% on another. VCAA applies statistical moderation so that school-based results can be compared across schools.
Your moderation group matters
The group normally includes students doing the same study at your school, or a school partnership. It is not necessarily just your classroom. External assessment, usually examinations, provides a common reference scale. VCAA uses the group’s results to align the school-based assessment scale.
Rank order is maintained
Moderation maintains the rank order supplied by the school. It aligns key points of the group’s school assessment distribution with the external distribution. It is more complex than giving each student the exam mark of another student at the same rank.
Your own exam is still your own
Your external assessment result contributes directly to your study score under the subject’s assessment weights. Its role in the moderation process is different from its direct contribution. You cannot infer your final moderated coursework just from your own exam result.
What school statistics cannot tell you
A school-wide median combines many studies and students. It does not describe your current subject’s moderation group. A calculator that adds points solely because your school has a higher median is making an unsupported assumption.
Source: VCAA statistical moderation.