Cross-Cultural Adaptation and Psychometric Validation of the Communication Complexity Scale (CCS) in Minimally Verbal...

This study aimed to translate, culturally adapt, and psychometrically validate the Turkish version of the Communication Complexity Scale (CCS) for minimally verbal children with autism spectrum disorder (ASD) and developmental delay (DD).

A total of 130 children aged 24-60 months (diagnosed according to DSM-5 criteria and recruited from developmental podiatric clinics) with fewer than 20 functional words (as verified through caregiver report and direct clinical observation) completed CCS sessions that were video-recorded and independently coded. Reliability was assessed using intraclass correlation coefficients (ICC), Cohen's kappa, and test-retest correlations. Concurrent validity was examined through correlations with the Turkish versions of the Communicative Development Inventory (CDI) and the Test of Early Language Development (TELD). Construct validity was tested with exploratory and confirmatory factor analyses (CFA). Known-groups validity compared Behaviour Regulation (BR) and Joint Attention (JA) scores between ASD and DD groups.

Most children demonstrated intentional non-symbolic communication, confirming the scale's sensitivity to minimally verbal behaviours. Inter-rater reliability was excellent (ICC = 0.86-0.91), and test-retest stability was strong (r = 0.88-0.93). CCS scores showed moderate correlations with standardized language measures (r = 0.39-0.42). CFA supported a one-factor model (RMSEA = 0.06; CFI = 0.93). Children with ASD had higher BR scores, whereas children with DD showed higher JA scores.

The Turkish CCS is a reliable, valid, and culturally appropriate tool for assessing communication complexity in minimally verbal children. Its sensitivity to non-symbolic and emerging symbolic behaviours support its use in clinical evaluation, individualized intervention planning, and cross-cultural research.

What is already known on this subject Minimally verbal children with autism spectrum disorder and developmental delay often communicate through non-symbolic behaviours such as gestures, eye gaze, and coordinated actions rather than spoken language. Conventional language assessments primarily target verbal output and therefore underestimate early communicative competence in this population. The Communication Complexity Scale (CCS) is an observational measure designed to capture hierarchical communicative behaviours from pre-intentional to emerging symbolic levels and has demonstrated strong reliability, validity, and sensitivity to change in English- and Mandarin-speaking populations. What this study adds to the existing knowledge This study provides the first culturally adapted and psychometrically validated Turkish version of the Communication Complexity Scale. The Turkish CCS demonstrated excellent inter-rater and test-retest reliability, strong construct validity supported by confirmatory factor analysis, and meaningful concurrent validity with standardized Turkish language measures. The scale successfully differentiated communication profiles between children with autism spectrum disorder and developmental delay, confirming its diagnostic sensitivity. These findings establish the Turkish CCS as a robust, culturally appropriate observational tool for assessing communication complexity in minimally verbal Turkish-speaking children. What are the potentials or actual clinical implications of this study? The Turkish CCS enables clinicians to systematically assess early communicative behaviours in minimally verbal children who cannot be accurately evaluated using standard language tests. By capturing intentional non-symbolic and emerging symbolic communication, the scale supports individualized intervention planning, goal setting, and progress monitoring. Its strong reliability and diagnostic sensitivity make it suitable for multidisciplinary clinical settings and early intervention programs. The availability of a validated Turkish CCS also facilitates inclusion of Turkish-speaking children in international research and promotes standardized, strengths-based communication assessment in clinical practice.