ACTA PSYCHOLOGICA, cilt.258, 2025 (SSCI, Scopus)
Purpose: The prevalence rates of Autism Spectrum Disorder are witnessing a steady increase worldwide, and the numbers for T & uuml;rkiye are remarkably high. Given the many potential cases that remain undiagnosed, there is a need to enhance the recognition of ASD, by ensuring the general population is kept informed about the condition. Determining the level of knowledge of ASD within the general population is crucial for the development of effective awareness-raising initiatives. However, in T & uuml;rkiye, there is currently a lack of assessment tools with cross-cultural validity that apply psychometrically sound methods to the measurement of the level of knowledge about ASD within the general population. In the present study we present a validation and reliability study of a Autism Spectrum Knowledge Scale translated for the Turkish context, as an internationally validated instrument for the measurement of knowledge about ASD within the general population. Methods: This quantitative study included 560 adults aged 18-71 years (M = 32.30, SD = 11.41) from various cities in T & uuml;rkiye. Data were collected via an online survey using a snowball sampling method. The study employed both Classical Test Theory (CTT) and Item Response Theory (IRT) to comprehensively assess the psychometric properties of the Autism Spectrum Knowledge Scale-General Form (ASKS-GF) in Turkish. Confirmatory Factor Analysis (CFA) was performed using the lavaan package in RStudio, utilizing a tetrachoric correlation matrix and the Weighted Least Squares Mean and Variance-adjusted (WLSMV) estimation method, given the categorical nature of the data. Model fit was evaluated based on the following criteria: chi(2)/df < 3, RMSEA and SRMR <0.08, and CFI and TLI > 0.95. Internal consistency was examined using Cronbach's alpha and McDonald's omega coefficients, while test-retest reliability was assessed by administering the scale to a subset of participants after two weeks. Criterion validity was examined by correlating ASKS-GF scores with the Knowledge of Autism Spectrum Disorders Scale. Results: