PSIV-34 Program Chair Poster Pick: Validating adapted scales to measure individual and situational interest in animal science undergraduates

Efforts to improve the quality of teaching and learning in animal science are forestalled by the lack of psychometric scales validated in our disciplinary context. Researchers have used instruments validated outside of animal science reliably, but this approach has questionable validity. The objective of our research was to adapt and validate scales to measure the motivational variables individual interest (II) and situational interest (SI) in introductory animal sciences students. A total of 254 introductory course students in two consecutive semesters rated their interest in animal sciences on unidimensional II (8-item) and 3-factor SI (11-item) scales previously validated for psychology undergraduates. After adapting instruments with wording specific to animal sciences, we conducted a series of confirmatory factor analyses. First, we discovered and removed two problematic items from the unidimensional II scale, offered theory-based explanations for differential item functioning in animal sciences students, and validated a revised II scale (λ = 0.74 - 0.94, CFI = 0.995, RMSEA = 0.027). Next, we confirmed the validity and reliability of the SI scale and its three subscales (λ = 0.83 - 0.96, CFI = 0.979, RMSEA = 0.048). Finally, to explore the dimensionality of SI in our population, we fitted a bifactor model and computed ancillary indices. Results supported the reliability and empirical validity of the bifactor model as an alternative conceptualization of SI (CFI = 0.986, RMSEA = 0.044). and indicated that the SI scale is mostly unidimensional (ω H = 0.923). This suggests that total SI scores can be used as a composite measure but that subscale scores are substantially contaminated by the general SI factor and should not be interpreted as unique. We present the finalized scales, recommendations for their use in animal sciences classrooms, and suggestions for future research.