Using Generalizability Theory to Investigate the Reliability of Scores Assigned to Students in English Language Examination in Nigeria

• Main Authors: Olufunke Favour AKINDAHUNSI, Eyitayo Rufus Ifedayo AFOLABI
• Format: Article
• Language: English
• Published: EPODDER 2021-06-01
• Series: Journal of Measurement and Evaluation in Education and Psychology
• Subjects: reliability; validity; english language; score; generalizability theory
• Online Access: https://dergipark.org.tr/en/pub/epod/issue/63232/820989

The study investigated the reliability of scores assigned to students in English language in National Examinations Council (NECO). The population consisted of all the students who sat for NECO Senior School Certificate Examination (SSCE) in 2017 in Nigeria. A sample of 311,138 was selected using the proportionate stratified sampling technique. The Optical Marks Record (OMR) sheet containing the responses of the examinees was the instrument for the study. The data was analyzed using lme4 package of R language and environment for statistical computing, factor analysis and Tucker index of factor congruence. The psychometric properties of the data were determined by estimating the generalizability (g) coefficient, phi (Φ) coefficient and construct validity. The results indicated the g-coefficient to be 0.90 and Φ coefficient as 0.87, which is an indication of high reliability of scores. The result also showed that a decrease in the number of the items resulted in a decrease in both g- and phi coefficients in D-study. The construct validity of 0.99 obtained from the result affirms the credibility of the items. Hence, it was concluded that the scores were dependable and generalizable.