DEVELOPMENT AND CALIBRATION OF A PRIMARY SCHOOL MATHEMATICS DIAGNOSTIC TEST BASED ON ITEM RESPONSE THEORY
IRT method has the capacity to produce item and person parameters that are, respectively, examinee and test sample independent. It was, therefore, the purpose of this study to develop and calibrate a Primary School Mathematics Diagnostic Test (PRISMADAT (Forms A and B)) based on IRT for use on primary four pupils. The design of the study was instrumentation. Seven research questions were posed and 10 hypotheses were formulated to guide the study. A sample of 4,844, selected through multistage cluster sampling plan from a population of 57,954 primary four pupils in Nasarawa State, during 2011/2012 academic session, took part in the study. The PRISMADAT (Forms A and B with 65 items on each form (totaling 130 items)) which was the main instrument in the study, was constructed based on the use of Primary School Mathematics Skills Deficiency Identification Test Blue Prints (MSDITBP’s).The MSDITBP’s were prepared based on the contents of the first four years (primaries 1-4) of the 9-year Basic Education Mathematics curriculum. Pilot study report showed that the PRISMADAT was unidimensional and had Cronbach Alpha reliability of 0.94. Data were collected from six local government areas (LGA’s) in Nasarawa State. Findings of the study showed that PRISMADAT Forms A and B are unidimensional and very reliable. Item difficulty parameter values range from -0.29 to 4.95 and from -0.97 to 3.21 for PRISMADAT Forms A and B respectively. Their discrimination parameters range from 0.19 to 4.70 and from 0.25 to 5.88 respectively. With regard to the guessing parameters, PRISMADAT Forms A and B, ranged from 0.00 to 0.38 and from 0.00 to 0.29 respectively. There was no sufficient evidence to show that a significant difference exists between the means of the parameters of items on PRISMADAT Form A and the means of corresponding parameters of items on PRISMADAT Form B. The conclusion was that a Primary School Mathematics Diagnostic Test (PRISMADAT Forms A and B) has been developed and calibrated based on the item response prtheory (IRT).