Abstract
There has been significant and extensive knowledge production in the last four decades regarding pragmatic language impairment (PLI) in children with neurodevelopmental disorders. The evidence contained in this literature, however, is contradictory. The present scoping review (ScR) seeks to disentangle competing explanations of conceptualizing, defining, and assessing PLI to develop more systematic knowledge suitable for improving early intervention and diagnosing PLI. Our research included retrieving articles, books, book chapters, encyclopaedia articles, and other published material on conceptualizing, defining, and assessing preschoolers' PLIs from online databases. A total of 133 studies have been identified, divided into two types: 63 studies conceptualizing and assessing PLI in preschoolers and 70 studies conceptualizing and defining PLI without regard to age. They were published between 1983 and 2022. The inclusion of studies in the first group was based upon factors such as the age of participants, clinical settings, and the use of PLI assessment instruments. The second group of studies was selected in accordance with Web of Science, Scopus, and Lens database indicators that indicated who were the most popular authors within the field. This review utilized the PRISMA-ScR (Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews) checklist and the Joanna Briggs Institute (JBI) guidelines. Results indicate that PLI is being conceptualized inconsistently. Three lists of concepts are reported here, with the earliest concept being "semantic-pragmatic syndrome" and the most prevalent being "PLI" without semantic features. Among the most common misconceptions of PLI is the use of impairment, disorder, deficit, dysfunction, disability, and many other concepts, both within the same publication and among different authors who have written numerous publications in this field. Researchers and clinicians are confused as to the nature of social (pragmatic) communication disorder compared to PLI, owing in part to its inclusion as a competing concept for PLI. As a final point, we argue that using different assessment methods for PLI is a promising approach to hope for consistency in conceptualizing, defining, and assessing PLI in children with neurodevelopmental disorders or others. The vast number of existing studies that seek to conceptualize, define, and assess PLI in preschool children with neurodevelopmental disorders and other conditions illustrates the broad interest in understanding more about the nature and occurrence of this impairment. Further, these studies also highlight some common patterns, discrepancies, and contradictions in relevant language that suggests researchers in all related fields should endeavour to be consistent in the way these concepts are defined and discussed to avoid miscommunication and confusion across and within the professions, as well as decrease the redundancy and overlap of related information. A consistent conception of language development disorders is necessary to obtain clarity in diagnosis, assessment, intervention, and rehabilitation.