The general aim of the thesis is to show how The Situational Language Intervention Programme (SLIP) was formulated in order to include the critical factors of: the cognitive abilities and linguistic characteristics of the intellectually handicapped; pragmatics, semantics and syntax and the four models of language acquisition; the criteria that guide language intervention programme development; the use of precise and systematic teaching methods that stimulate the use of language in the students' environment. The general objective of both SLIP and this thesis is to show how to increase moderately to severely intellectually handicapped adolescents' language-communication through the appropriate use of the forms of language applied to its functions in a specific range of situations. Chapter Two of the thesis is concerned with the cognitive abilities of intellectually handicapped people and the implications of intellectual handicap on communication and language development. In addition it discusses, stage by stage, the positive and negative markers of language acquisition. These markers illustrate to the teacher the signs of linguistic retardation at each stage of language learning. The contents of Chapter Three provide an outline of the four models of language acquisition, i.e. Pragmatic, Semantic/Cognitive, Psycholinguistic/Syntactic and Behavioural. Those models contribute to our understanding of how language develops and illustrate to us the complex nature of language acquisition. In addition, this discussion documents the past and current research viewpoints and draws our attention to the limitations that existing theories have in providing a "full�blown" model of language acquisition. Furthermore, Chapter Three is stating that the recent analysis of language-training for communication disordered and intellectually handicapped students has shown that a more balanced study of the semantic and pragmatic factors in language acquisition is emerging. This chapter is urging teachers to re-analyze, re-evaluate and modify their language intervention programmes by integrating the syntactic, semantic and pragmatic factors. Both the contents of Chapters Two and Three are demonstrating that it is necessary to address the theoretical viewpoint and academic findings both of which are important aspects of the role of the interventionist. They have to be addressed if the teacher is to make judgments concerning the efficacy of different models in attaining certain goals. Such factors govern the utilization and integration of certain approaches and procedures. The contents of Chapters Four and Five discuss how the language interventionist can lead the intellectually handicapped student into increased language usage and communicative competence. Chapter Four is concerned with the current critical issues and developments in: curriculum and programme design for the moderately/severely intellectually handicapped adolescent; criteria to guide programme development and direction of language intervention; direct instruction techniques; augmentative communication systems and their basic programme guidelines. Chapter Five outlines the framework of the Situational Language Intervention Programme (SLIP) which was designed and implemented by the author. The content and procedures utilized by SLIP are greatly influenced by the contents of Chapters Two, Three and Four. This influence is demonstrated in the discussion concerning SLIP's: aims and objectives; content and design decisions; selection of forms to be taught; sequencing; teaching procedures and methods of instruction. Chapter Five also discusses the implementation of SLIP.

In 1980 Jackson and Knowles presented a paper at the Australian Group for the Study of Mental Deficiency [A.G.S.O.M.D.] conference in Launceston, Tasmania. The paper, titled "Primary School Children's Perceptions and Understandings of Mental Retardation", reported in detail responses on twenty questions from the sixty-three item questionnaire instrument used in their study. These twenty questions reflected stereotyped responses of an alarming nature. If these responses were a reflection of how Australian children generally thought, then integration of the intellectually handicapped child into mainstream classes would be counter productive. The current study was initiated to help assess the attitudes of Australian Capital Territory children to the Intellectually Handicapped. The twenty significant questions from the Tasmanian study were formed into a questionnaire and administered to 769 children in Years 3 and 6 from six Government and two Catholic schools in the Australian Capital Territory. In most cases the results were in direct contrast to those obtained in Tasmania. At first glance this meant that the attitudes of Australian Capital Territory children towards the Intellectually Handicapped were much less stereotyped than those of Tasmanian children. Further investigation, however, led to the discovery that the results from the Tasmanian study were spurious. The date had not been accurately computerized, giving a result that was probably the reverse of what Tasmanian children actually thought. Four supplementary hypotheses, comparing the responses of Years 3 and 6 girls and boys, Government and Private schools, exposed and unexposed schools, were tested. The analysis of the data for these hypotheses supported, to some degree, past findings that older children and girls have less stereotyped attitudes towards the Intellectually Handicapped than younger children and boys. The responses of Government schools versus Private schools were varied. Three of the five significantly different responses indicated a less stereotyped view was held by Government school children, while two of these significant questions indicated a less stereotyped view was held by Private school children. With regard to exposed and unexposed schools, the two significantly different responses indicated less stereotyped views were held by the nonexposed children. Future directions are indicated in the sections dealing with Limitations and Future Directions.

Some syntactic aspects of the oral language of 20 mildly intellectually handicapped, 20 normal seven year old and 20 normal ten year old children were examined in order to determine the comparative development of the mildly intellectually handicapped children and some of the difficulties they might experience. The language was classified into 24 categories for various types of analysis. These types included traditional counts and an examination of the types of subordination as well as of non-conventional usage. In addition, Developmental Sentence Scoring (Lee : 1974) was used to assess the maturity of personal pronoun and main and secondary verb usage. The sentence repetition technique was employed as a means of assessing competence in a variety of later-developing structures. Questions were designed to assess ability in other specific syntactic areas. Analysis of variance was used to compare group scores and determine if any significant differences occurred. Several significant differences did occur. The findings provided strong evidence that the language of mildly intellectually handicapped children is more like that of children of the same chronological age than it is like that of children of the same mental age and that it is less mature than the former. These handicapped children experience considerable delay in the development of pronouns and verbs and have a high incidence of non-conventional usage. This study also provided evidence of the continuing language development of normal primary age children. Some methods of sampling and analysing oral language were found to be of particular value. Of these the sentence repetition technique seems promising both as a research tool and as a classroom instrument for assessing individual children's language competence. The importance of this and similar research lies in its implications for educational programming.