Abstract:
Differential item functioning (DIF) occurs when individuals of the
same ability level from separate groups have a different probability of
answering an item correctly. This study was conducted in two parts: in the first
part a real 2015 West African Senior Secondary Certificate Examination
(WASSCE) core mathematics test data were analyzed for uniform and non-uniform DIF using binary logistic regression (LR) procedure and in the second
part, content analysis of items identified as DIF were classified under the
levels of the cognitive domain by experts. Three research questions were
formulated for the study. A sample of 4,285 male and 3,712 female candidates
were selected from a population of 15,258 candidates who sat for the
examination in 2015 from 20 selected schools in Southern Ghana. The
instrument for the study was the 50 multiple-choice core mathematics items.
The findings showed that there was 43 significant gender differential item
functioning items of which 9 were uniform and 34 non-uniform. Also, the
content analysis revealed that items that favoured males were mainly number
and numeration, algebraic processes, probability and statistics and
mensuration whiles plane geometry and coordinate geometry revealed DIF in
favour of females. It was concluded that test items used were not free from
gender DIF. It was recommended that DIF studies should be conducted by test
developers in order to be review or exclude DIF items to enhance fairness in
assessment.
