Psychometric validation of the lecturers’ academic motivation scale using Item Response Theory: insights from Malaysia and Japan

Considering the growing importance of lecturers’ academic motivation as a key socio-psychological attribute, this study examined the psychometric properties of the Lecturers’ Academic Motivation Scale originally introduced by Machado-Taylor et al. (2016). Using data collected from lecturers in Malaysian and Japanese public and private universities, the Graded Response Model (GRM) within the Item Response Theory (IRT) framework was applied. The analysis refined the original six-item scale into a refined five-item version, with item and test information curves indicating that the scale provides the most useful information within the academic motivation range of approximately θ = −3 to θ = 2. Although a moderate dip in information values was observed near the mean, the scale offered substantial coverage across this effective range. Beyond θ = 2, the amount of information diminished sharply, which is less consequential in practice given that only a very small proportion of respondents are likely to exhibit such high levels of academic motivation. Overall, the refined scale proved to be reliable and informative across the range where the majority of individuals in the population are expected to fall. Importantly, none of the five items showed bias by gender or university type, highlighting the scale’s consistency and fairness across different groups. The implications of these findings are discussed, along with the scale’s limitations, and the importance of incorporating cross-cultural perspectives in future research on academic motivation.