The Social Language Development Test-Adolescent: Normtaive Update (SLDT-A:NU) is a diagnostic test of social language skills, including nonverbal communication, for adolescent students between the ages of 12:0 and 17:11.  The tasks assess social language skills such as a student’s ability to make inferences, and interpret and respond to social interactions.  Performance on this measures differentiates typically developing students from those with autism spectrum disorder. The assessments consits of five subtests which are scored seperately and together yield a composite score and a scaled score Social Language Development Index.