Examination of the psychometric properties of physical activity enjoyment scale (PACES) based on classical test theory and item response theory

Enjoyment of physical activity is a key factor influencing exercise and sports participation. This study aimed to examine the psychometric properties of the Turkish adaptation of the Physical Activity Enjoyment Scale (PACES-8) using Classical Test Theory (CTT) and Item Response Theory (IRT). The sample consisted of 835 healthy adults aged 18 to 35 years (M = 23.86, SD = 3.90), including 492 males (58.9 %) and 343 females (41.1 %). Data were analyzed using R software (version 4.3.2). Confirmatory factor analysis under CTT indicated a good model fit, with CFI = 0.99 and RMSEA = 0.07. Similarly, the IRT-based confirmatory analysis demonstrated excellent fit indices, with CFI = 0.994 and RMSEA = 0.078. Item discrimination parameters were very high (a = 5.25-9.27), and item fit statistics were satisfactory. The scale effectively differentiated individuals with physical activity enjoyment levels between -3.5 and 0; however, it showed limited discrimination among individuals with higher levels of enjoyment due to a ceiling effect. High correlations were observed between raw scores and scores derived from both CTT and IRT models (r ≥ 0.94). Differential item functioning analysis by sex revealed no significant or practically meaningful bias. In conclusion, the Turkish version of PACES-8 is a valid, reliable, and gender-fair instrument for assessing enjoyment of physical activity. To enhance its discriminative power at higher enjoyment levels, it is recommended to develop additional items that capture deeper emotional and motivational aspects of enjoyment.