“…These assumptions are essential in a rigorous IRT analysis. Given the emerging interest among empirical studies in reporting behavior problems at these two subscale levels (e.g., Hammam, et al, 2020; Quiñones-Camacho, et al, 2021; Rodrigues et al, 2022; Steenhoff et al, 2021), a more comprehensive IRT study on the externalizing and internalizing subscale scores is needed, To our knowledge, this is the first study applying IRT analysis to examine the psychometric properties of the CBCL/1½ – 5 among preschool children, particularly those who are from low-income population.…”