Evaluating the Power of Questions: Unpacking the Validity and Reliability of a Questionnaire on Case-Based Learning and Traditional Ecological Knowledge

Students need meaningful learning to understand and internalize the knowledge they receive by relating what they know from their local environment with the new science concept they learn, in this study we call it Traditional Ecological Knowledge (TEK) integrated with case-based learning (CBL). However, the use of this integration needs to be measured by the correct instrument to make sure that it is measuring the correct target. Thus, this study was done to evaluate the validity and reliability of the 24-item questionnaire used in this study by using the Rasch Model analysis. The respondents were 73 students programming STEM courses and the data was collected by using a questionnaire in a Likert scale of 1 to 4. The results show that the percent agreement for each aspect is more than 90%, with the highest score in the structure of the instrument consisting of accuracy, clarity, and usefulness of the items and the overall percent agreement validity is 93.15%. Meanwhile, the validity of the instrument measured with Rasch analysis results on an acceptable validity (>20%) and the reliability of the instrument is considered as good (0.89) with the retained items as many as 12 items. The results imply that the questionnaire used in this study is valid and reliable to measure the implementation of integrated learning between case-based learning and traditional ecological knowledge.