Abstract
Background/Objectives: Many studies have investigated the Cognitive Acceleration through Science Education (CASE) programme, demonstrating its impact on students' reasoning and learning development across different educational contexts. Likewise, numerous experimental investigations have employed the Solomon Four-Group Design (SFGD) to control for pretest sensitisation and improve the validity of intervention studies. However, despite the extensive use of both frameworks independently, no previous research has integrated them within a single study. The present research therefore combines the theoretical foundations of CASE with the methodological rigour of the SFGD to explore the influence of intervention outcomes under different pretest conditions on learners' cognitive growth. Methods: This study examines differences associated with pretest sensitisation and the CASE programme among middle school students using a quasi-experimental research design. The study was conducted with 88 students divided into four groups, two experimental and two control, following the Solomon Four-Group Design to account for pretest sensitisation and its potential interaction with the treatment. Results: Statistical analyses revealed that the observed outcomes differed between pretested and non-pretested groups, with the pretested conditions showing larger post-test differences than the non-pretested ones. Conclusions: Rather than establishing causal effects, this study highlights key methodological considerations related to pretest sensitisation when evaluating cognitive acceleration interventions. The findings provide practical guidance for researchers and educators in designing, analysing, and interpreting classroom-based intervention studies where pretesting may influence observed outcomes.