ABSTRACT
Within the general theme of the present volume, language competence across populations, this first section takes a special focus. It concentrates on one particular population, namely, children with specific language impairment (SLI). Specific language impairment has been studied for several decades, and is viewed by many researchers as a disorder distinct from other (language) disorders. However, as several contributions in this volume show, it is not always clear in what sense the language characteristics of children with SLI are different from those of children with other disorders. Thus, it is important to investigate the differences and similarities in linguistic behavior between the various populations. This provides more insight into the possible specificity of the disorders, as well as into the general constraints on language development. In order to maintain the hypothesis that SLI is a distinct disorder, it is necessary to create a set of exclusionary and inclusionary criteria on the basis of which the disorder can be isolated. The chapters in this section contribute to this goal.
