Effect of Case Study-Based Assessment Method on Grade 9 Learners’ Problem-Solving Competency in Food Production Processes: Evidence from a Solomon Four-Group Quasi-Experimental Study in Kenya

This study examined the effect of case study assessment on problem-solving competency among Grade 9 learners in food production processes within Kenya’s Competency-Based Education context. A quasi-experimental Solomon Four-Group design involving 335 learners selected through multi-stage cluster sampling was adopted. Data were collected using a validated skill test based on video-based agricultural scenarios, with acceptable reliability (Cronbach’s alpha = 0.751). One-way ANOVA was used to examine baseline equivalence and intervention effects. Results showed no significant pre-intervention differences among groups (p > 0.05). Following the intervention, learners exposed to case study assessment demonstrated significantly higher problem-solving skills than those using conventional assessment methods (p < 0.001), with a large effect size (Cohen’s d = 0.86; ω² = 0.429). The findings demonstrate that case study assessment enhances applied reasoning and decision-making, supporting its integration into competency-based agriculture education.