Abstract
Terms suggested for unexpected language learning difficulty include specific language impairment, primary language disorder and language learning disability; however, none of them represents the critical element of literacy. Some experts have suggested that debating what to call language disorders is parallel to debating what to call reading disorders and dyslexia. In contrast, it is argued here that reading disorders are language disorders and not separate or parallel. Evidence is presented for quadrant models that explain language disorders and dyslexia along two dimensions—sound/word level (phonological) knowledge and sentence/discourse level (non-phonological) knowledge. Support for these two dimensions comes from factor analysis of a new assessment tool called the Test of Integrated Language and Literacy Skills (TILLS). Two case studies illustrate how a quadrant model can be used to explain patterns of abilities that vary along these two dimensions to parents and teachers. The article concludes with a recommendation to adopt a label that reflects language/literacy commonalities rather than differences, such as language/literacy disorder or specific language/literacy impairment.
Acknowledgement
This paper is based on an invited keynote address of the same name presented at the Annual Conference of Speech Pathology Australia in Canberra, Australia, May 2015. The research reported in this work was supported by the Institute of Education Sciences, U.S. Department of Education [grant number R324A100354]. The author appreciates contributions by grant coordinator, Dr. Michele Anderson, and co-investigators, Dr. Elena Plante and Dr. E. Brooks Applegate.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.