Abstract The Social Communication Assessment for Toddlers with Autism (SCATA) was designed to measure non-verbal communication, including early and atypical communication, in young children with autism spectrum disorder. Each communicative act is scored according to its form, function, role and com- plexity. The SCATA was used to measure communi- cative ability longitudinally in two samples of toddlers with autism spectrum disorder. Overall frequency of non-verbal communicative acts did not change between the two assessments. However, the form and complexity, the function and the role the child took in the interaction did change with time. Both frequency and function of communicative acts in toddlerhood were positively associated with later language ability: social acts, comments and initiations showed greater predictive association than requests and responses. Keywords Autism Æ PDD Æ Non-verbal communication Æ Social-communication Æ Measurement Æ Assessment Introduction It has long been recognised that impairments in non- verbal communicative behaviours are characteristic features of children with autism (Rutter, 1978; Wing, 1976) and they are now included as part of the formal diagnostic criteria (DSM-IV-TR; APA, 2000; ICD-10; WHO, 1993). A large body of research over the past 20 years has demonstrated that they are important in the early identification and diagnosis of autism (for reviews see Charman & Baird, 2002; Filipek et al., 1999). Not only do children with autism show impair- ments in non-verbal communication compared to comparison groups, but within groups of children with autism, individual differences in non-verbal communi- cation are also associated with later language and so- cial outcomes (Charman et al., 2003; Mundy et al., 1990; Sigman & Ruskin, 1999; Stone & Yoder, 2001). For these reasons they are important in the clinical assessment of toddlers referred for possible autism. Several instruments have been developed to mea- sure non-verbal communication in young children with autism, including the Autism Diagnostic Observation Schedule Generic—Module 1 (ADOS-G; Lord et al., 2000), the Communication and Symbolic Behavior Scales (CSBS; Wetherby & Prizant, 1993), the Early Social Communication Scales (ESCS; Mundy, Hogan & Doehring, 1996) and the Screening Tool for Autism in Toddlers (STAT; Stone et al., 2000, 2004). Although these instruments vary somewhat in the specific non- verbal communication behaviours measured, they all consist of a series of structured interactions between an adult and a child in which a variety of play materials and social presses are employed in order to elicit social and communicative interactions with the child. The A. Drew Æ G. Baird Newcomen Centre, Guy’s Hospital, London, UK E. Taylor Æ T. Charman (&) Behavioural & Brain Sciences Unit, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK e-mail: t.charman@ich.ucl.ac.uk E. Milne Department of Psychology, University of Sheffield, Sheffield, UK J Autism Dev Disord (2007) 37:648–666 DOI 10.1007/s10803-006-0224-9 123 ORIGINAL PAPER The Social Communication Assessment for Toddlers with Autism (SCATA): An Instrument to Measure the Frequency, Form and Function of Communication in Toddlers with Autism Spectrum Disorder Auriol Drew Æ Gillian Baird Æ Emma Taylor Æ Elizabeth Milne Æ Tony Charman Published online: 19 October 2006 Ó Springer Science+Business Media, Inc. 2006