Nonlinear relationship between weekly study hours and academic performance among students at School of Statistics and Planning in Makerere University

Abstract

Many students and advisors assume that more weekly study hours always lead to higher grades yet evidence from other settings suggests that the returns to study time may diminish beyond a point. This study examined the nonlinear relationship between weekly study hours and academic performance among undergraduate students at the School of Statistics and Planning, Makerere University and tested whether an optimal study-hour threshold exists. A quantitative cross-sectional design was used. Primary data were collected from year 2 and year 3 students across four programmes through a structured online questionnaire on KoBoToolbox. A total of 224 students provided complete and usable responses. Cumulative grade point average (CGPA) was regressed on mean-centred weekly study hours, its square, sleep hours, class attendance, part-time work, physical exercise, sponsorship status and age using polynomial ordinary least squares in Stata. Multicollinearity and heteroskedasticity checks were satisfied. Students had a mean CGPA of 3.90 and studied on average 18.34 hours per week. The squared study-hours term was not statistically significant with p value 0.450, so there was no evidence of a curvilinear relationship and no optimal threshold could be identified within the observed range of 1 to 40 hours. Weekly study hours showed a small positive linear association with CGPA with p value 0.017. After controlling for study hours, attendance, sleep hours, age and scholarship compared with private sponsorship were significantly associated with CGPA while government sponsorship, physical exercise and part-time work were not. The model explained about 32% of the variation in CGPA R² = 0.322 and was jointly significant F (8, 214) = 11.31and p value less than 0. 001.In this sample regular class attendance was significantly and positively associated with CGPA after controlling for study hours and there was no evidence that studying more reduced performance. Academic advisors should emphasise attendance and adequate sleep alongside effective use of study time and future studies should use larger multischool samples and administrative CGPA records.