Abstract
This study examined the prevalence of aberrant response patterns in mathematics achievement tests among secondary school students in Southwestern Nigeria. The study used a multi-stage sampling technique to select 1800 Senior Secondary School students for its survey research sample. From the six states in Southwestern Nigeria, three states, one senatorial district, and three Local Government Areas were selected from each state using a simple random sampling technique. Using a stratified sampling technique, four secondary schools, and fifty senior secondary school students were selected. The mathematics achievement test was used to collect data for the study. Data collected were analyzed using MATLAB to compute aberrance indices and SPSS. The results showed that there is a high prevalence of aberrant response patterns with W* (x ̅ = 2.07, sd = 1.71) had a lower value of mean and standard deviation than the B* (x ̅= 3.61, sd = 3.34). The study also revealed that there was a significant difference between the aberrant and non-aberrant students for W* (t =-13.91, df =1693, p<0.05) and B* (t = -14.79, df =1693, p< 0.05). The study further revealed that sex (p-value= 0.026, R-squared= 0.003, Adjusted R-squared=0.002), age (p-value = 0.035, R-squared = 0.001, Adjusted R-squared= 0.001), and school type (p-value= 0.044, R-squared= 0.004, Adjusted R-squared= 0.003) have significant effects on students’ aberrant response pattern. The study concluded that there is a high prevalence of aberrant response patterns among secondary school students in Southwestern Nigeria