Orinemi Dennis Horsfall & Professor William J. Ubulom
Psychometric Investigation of the 2025 WAEC English Language Objectives Test of Public Senior Secondary School Students in Rivers State
Abstract
This study investigated the validity, reliability, guessing parameters, and ability estimates of the 2025 West African Senior School Certificate Examination (WASSCE) English Language multiple-choice objective test of public senior secondary school students in Rivers State. A descriptive survey research design was adopted. The population comprised 59,223 SS3 students, from which 500 students were selected using a multi-stage sampling technique. Data were collected using the 2025 WASSCE English Language objective test. The validity of the instrument was assumed to have been established by WAEC through expert test development procedures, while a pilot study yielded a Kuder–Richardson Formula 20 (KR-20) reliability coefficient of 0.80. The instrument was administered under standardized examination conditions. Data were analyzed using Classical Test Theory (CTT) and Item Response Theory (IRT). Validity was assessed using Exploratory Factor Analysis, reliability using KR-20, guessing using the three-parameter logistic (3PL) model, and students' ability using theta (θ) estimates. The findings revealed that the test demonstrated acceptable validity, satisfactory reliability, generally low to moderate guessing effects, and effectively differentiated candidates across varying ability levels. The study concluded that the examination possessed acceptable psychometric quality but required improvement in a few highly guessable items and the inclusion of more difficult items. It was recommended that WAEC should strengthen routine psychometric validation, monitor reliability, revise highly guessable items, and include more difficult items to improve measurement precision.
