A Pilot Study Examining the Test–Retest and Internal Consistency Reliability of the ABLLS

The literature contains a variety of assessment tools for measuring the skills of individuals with autism or other developmental delays, but most lack adequate empirical evidence supporting their reliability and validity. The current pilot study sought to examine the reliability of scores obtained from the Assessment of Basic Language and Learning Skills–Revised (ABLLS-R). Two forms of reliability were measured: internal consistency and test–retest reliability. Analyses using data obtained from neuro-typical children (N = 50) yielded strong evidence of internal consistency and test–retest reliability. These preliminary findings suggest that the ABLLS-R can yield reliable scores