Word learning is a vital aspect of children's language development. However, many children with autism spectrum disorder (ASD) have enormous difficulty learning words and approximately 30% have virtually no language at 9 years of age. As ASD affects 1 in 68 children worldwide, investigating why so many of these children struggle to learn words is a global research priority and a necessary precursor to designing effective interventions.This project will explore multiple stages of word learning in minimally-verbal children with ASD in order to isolate the source, or sources, of their difficulties. In a series of experiments involving children with ASD and children with typical development, we will compare how these groups (a) identify the meanings of unfamiliar words, (b) retain the meanings of words over time, and (c) generalise words to novel contexts. We will also assess how these stages of word learning are influenced by autistic children's reduced sensitivity to informative social cues, such as gaze and gesture. Based on these novel data, we will develop a new integrative account of word learning deficits in ASD that incorporates multiple aspects of word learning and how they are influenced by social difficulties. This account will be supported by a new computational model simulating a child with ASD learning new words. The model will indicate how the stages of word learning might interact to produce the problems observed in children with ASD. Consequently, this modelling will provide insight that could not be obtained by simply observing behaviour. Moreover, it will yield numerous theoretical hypotheses for future research and provide a basis for predicting the effects of new interventions that may promote word learning in children with ASD. The findings from this research will have important implications for practice in Special Education. By examining multiple aspects of word learning, our studies will identify specific weaknesses that can be targeted by interventions and strengths to capitalise on. We will also discover whether word learning in children with ASD can be improved by directing their attention and identify the best way of doing this (e.g. social or non-social cues). Crucially, this project will provide a necessary foundation on which to develop new evidence-based interventions that scaffold each stage of word learning, thus providing optimal learning conditions for children with ASD.