Validation of the Cognition Scale of the Hong Kong Comprehensive Assessment Scales for Toddlers

<b>Background/Objectives</b>: This study aimed to examine the psychometric properties of the Cognition Scale of the Hong Kong Comprehensive Assessment Scales for Toddlers (HKCAS-T) including its measurement properties, concurrent validity, and reliability. <b>Methods</b>: Participants included 282 children aged 18 to 41 months. These children were assessed on the HKCAS-T and the Cognitive Scale in the Cognitive Battery of the Merrill-Palmer-Revised Scales of Development (M-P-R). For test-retest reliability, 41 children were reassessed four weeks after the initial assessment. <b>Results</b>: Rasch analysis supported the unidimensionality of the HKCAS-T Cognition Scale. The scale differentiated among children of different ages, with older children achieving higher scores. The HKCAS-T Cognition Scale scores also correlated positively with the Cognitive Scale scores in the Cognitive Battery of the M-P-R. Internal consistency and test-retest reliability were both 0.98. <b>Conclusions</b>: The Cognition Scale of the HKCAS-T demonstrated strong psychometric properties and shows promise as an assessment tool for toddlers.