Application of item response theory in the development and validation of a multiple-choice economics test for senior secondary school students

This study applied Item Response Theory (IRT) to develop and validate a multiple-choice Economics test for senior secondary school students. An instrumentation research design was adopted. A total of 1,005 SS2 Economics students were randomly selected from 46 government co-educational secondary schools in Nsukka Education Zone, Enugu State, Nigeria. A 50-item Multiple Choice Economics Test (MCET) was developed, validated by experts, and pilot-tested, yielding a reliability coefficient of 0.89 (KR-20). Data were analyzed using the three-parameter logistic (3PL) IRT model with BILOG-MG software. Results showed that 49 items demonstrated low standard errors of measurement, indicating high precision, while one item showed low reliability. Item fit analysis revealed that 21 items fit the 3PL model, whereas 29 items misfit. Differential Item Functioning (DIF) analysis indicated that most items functioned differently across gender. The findings demonstrate IRT’s usefulness in identifying reliable, misfitting, and biased items, supporting evidence-based item revision. The study recommends adopting IRT principles in Economics test development to enhance reliability, validity, and fairness.