Developing Grade 10 Learners’ Hypothetico-deductive Reasoning through Teacher-made Thought Experiments and Hypothesis-testing Activities

Abstract

Background: Developing learners’ ability to formulate hypotheses, interpret evidence, and draw logically warranted conclusions is central to science education. However, classroom materials that explicitly integrate thought experiments with hypothesis-testing activities remain limited in many secondary-school settings. Aim: This study developed and evaluated teacher-made thought experiments designed to strengthen the hypothetico-deductive reasoning of Grade 10 biology learners. Method: A two-group pre-test–post-test design was used with 52 learners from a public secondary school in Iligan City, Philippines. Participants were assigned to treatment and control groups of 26 learners each. Seven hypothesis-testing activities aligned with the K–12 science curriculum were developed, validated by science teachers and content experts, and implemented in the treatment group. The control group received instruction based on the learner’s manual. A validated 15-item multiple-choice test was administered before and after instruction, and the data were analysed using descriptive statistics and an independent-samples t-test at the 0.05 significance level. Results: Both groups showed significant improvement from pre-test to post-test. The treatment group obtained a higher post-test mean score than the control group (14.36 versus 13.69), producing a mean difference of 0.67. However, the between-group difference was not statistically significant (p = .150). Conclusion: The teacher-made activities supported the development of hypothetico-deductive reasoning and may serve as useful supplementary guided-inquiry resources. Nevertheless, the findings do not establish their superiority over instruction based on the learner’s manual. Further studies with larger samples, stronger measurement procedures, and monitored implementation fidelity are warranted.