Analysing the Psychometric Properties of Mathematics in Public Examinations in Nigeria

Abstract

This paper investigated the psychometric properties of Mathematics examinations conducted by four examination bodies (NABTEB, NECO, JAMB and WAEC) to establish the quality of the items presented to secondary school students for of the purpose of certification and placement.  The study employed descriptive survey research design to seek for information from a segment of the population of senior secondary students to make generalization on all Nigerian students adopting the multistage stratified sampling technique. From each of the 6 geo-political zones, 2 states were randomly selected to obtain a total of 12 states.  One co-educational Federal Government College was purposively sampled from each state, plus three public schools, one private secondary school and one technical college were selected from each state. Thirty SS3 students selected, using the systematic random sampling technique in each of the sampled schools that have been presenting students for public examinations.  The test batteries were past question papers developed in four common subjects offered in public examinations as listed above.  The statistical tools employed to provide empirical answers to the research questions are: calculation of difficulty indices using relevant formula; split half correlation, Distractor power estimate, and Discrimination indices using relevant formula, also quantitative validations of test were conducted. A fairly high proportion of the test items have appropriate difficulty index i.e. within ranges 0.25 – 0.75.  Validity of test batteries used was fairly good.  Other psychometric characteristics were found to be generally acceptable.  It is recommended that, for easy tests, attention should be given to higher order skills required of graduate of secondary schools and coverage of most aspects of the syllabi prescribed by examination bodies.  It is also recommended that the present standard of examinations in Nigeria should be sustained and improved upon.

Keywords:Psychometric properties, Public Examinations, Distractor Power, Discriminative Index, Reliability, Validity.