The ability to learn new words is critical in the development of oral and written language, and significantly impacts engagement in social, academic and vocational situations. Many studies have evaluated the word-learning process in people with developmental language disorder (DLD). However, methodologies for assessment are heterogeneous, creating difficulties in synthesizing findings and identifying gaps in the knowledge base. To scope systematically the literature and identify key methodological parameters considered in evaluations of word learning in people with DLD; and to identify gaps in the literature to guide further research in this area. Twelve databases were searched and a total of 70 studies that met eligibility criteria were identified. The studies were evaluated according to key parameters that researchers varied in their word-learning methodologies. Most research has focused on word learning in the oral modality, and specifically in children with DLD. Fewer studies have explored word learning in adults and adolescents with DLD, and in the written modality. Depending on the research question and theoretical perspective driving the investigation, methodologies for assessing word learning considered a range of parameters, including words being learned, learning context and cues to support learning in the tasks. This review aggregates a variety of methods used previously to assess word learning. Findings highlight the need for further research to explore areas such as: the learning of varied word types (e.g., adjectives and adverbs); learning in the written modality; and word learning (both oral and written) in adolescents and adults with DLD.
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