Visual method for explaining De Morgan’s Laws in upper secondary education

This study examined the effectiveness of visual methods in teaching De Morgan's Laws to upper secondary students. It explored how Venn diagrams, graphic models, and interactive digital simulations support conceptual understanding, motivation, and logical thinking in Boolean logic and set theory. Using a single-group pretest–posttest design, 135 students in Kosovo completed achievement tests and an attitude questionnaire. Paired-samples t -tests and Pearson correlation analyses (SPSS) showed significant improvement in posttest performance and highly positive student attitudes, particularly regarding conceptual clarity and ease of learning. A strong positive correlation between attitudes and achievement indicated that favorable perceptions of the visual method were associated with higher academic outcomes. Although the absence of a control group and the single national context limit generalizability, the findings suggest empirical support for integrating visual tools, including Venn diagrams and GeoGebra simulations, to enhance understanding of abstract logical concepts and promote critical and creative thinking in mathematics education.