Validation Study of a General Subject-matter Interest Measure: The Individual Interest Questionnaire (IIQ)

Importance: Interest is considered a significant educational construct. A validated instrument that can reliably be used to measure interest across different subject domains is however not available. Objective: To report the findings of two studies that were conducted to test the validity and reliability of a newly designed Individual Interest Questionnaire (IIQ). Design: Study 1 was a construct validation study involving three independent high school samples from different disciplines. In Study 2 the predictive validity of the IIQ was tested by examining how well the IIQ predicts cognitive engagement and on-task behaviors and attitudes of students. Participants: A sample of 230 chemistry, geography, and history high school students (Study 1) and 82 biology high school students (Study 2). Setting: High schools in Singapore. Main outcome measures: Confirmatory factor analysis, Hancock's coefficient H, test of multi-group invariance, cognitive engagement and on-task behaviors and attitudes (i.e., curiosity, enjoyment, self-efficacy, attention, and boredom). Results: Confirmatory factor analysis for the three samples suggest adequate fit of the data with the hypothesized model: History: χ2 /df¼1.47; p¼.13, RMSEA¼.08, CFI¼.96; Chemistry: χ 2 /df¼1.41; p¼.17, RMSEA¼.07, CFI¼.98; and Geography: χ 2 / df¼1.51; p¼.11, RMSEA¼.09, CFI¼.94. Reliability analysis revealed high levels of reliability of the IIQ: coefficient H History: .81; coefficient H Chemistry: 85; and coefficient H Geography: .85. The test for multi-group invariance was ns, suggesting that the factor structure of the IIQ was invariant across the three subjects. The data fitted the predictive path model well: χ2 /df¼1.60; p¼.11, CFI¼.98, RMSEA¼.09 and the standardized regression weights of individual interest for the outcome measures ranged from: .69 (po.001) cognitive engagement to .24 (p¼.03) boredom. Conclusion and relevance: The results suggest that the IIQ is a reliable and valid instrument to measure individual interest across different disciplines and demonstrated adequate predictive validity for cognitive engagement and on-task behaviors and attitudes. The IIQ fills the gap in the literature for a generic instrument to measure individual interest.