A Rasch analysis of the quality of marking of GCSE Science
The reintroduction of an examination that combines biology, chemistry and physics has created the potential for a reduction in the reliability of marking. A Rasch analysis was conducted to explore whether the reliability of marking of science exams was being compromised by having markers mark outside their specialism.
This paper concludes that the differences between specialisms are minor at worst. Therefore there is no pressing need to split the marking of expert marked items by subject specialism. The most important factor in ensuring high marking reliability is likely to be the clarity of the mark scheme and the training of markers. Clear thought and planning should be used to ensure mark schemes are fit for purpose to allow marking to be completed reliably.