LASS: Summary of Research and Supporting Scientific Evidence

LASS is a suite of computerised tests designed for the assessment of literacy and cognitive skills in the age ranges 8 to 11 and 11 to 15 years.  The LASS suite for each age group comprises eight standardised tests of reasoning, reading, phonic decoding, spelling, memory (visual and verbal), and phonological awareness.  These tests have been developed in order to provide teachers with an easy-to-use method for identification of dyslexia and other learning problems.

As with all of Lucid’s products, the tests in LASS were produced in accordance with the highest international test development standards, including procedures for item creation and refinement, psychometric validation and national standardisation to create robust norms.  The initial research to develop LASS was carried out using over 2,300 students throughout the UK.  Additional standardisation samples totalled 1107 children in 11 schools for LASS 8-11 and 505 students attending 14 schools for LASS 11-15, selected to give a nationally representative spread of types of school, levels of achievement and socio-economic advantage/disadvantage.  Student selection procedures conformed to recognised international test development standards to ensure no sample bias.  For further details regarding standardisation see Section 1.3 of the LASS 8-11 Teacher’s Manual  and Section 2.2.1 of the LASS 11-15 Teacher’s Manual.

Dr Joanna Horne of the Psychology Department, University of Hull carried out a concurrent validity study of LASS using 75 students attending five different schools in different regions of the UK.  The students’ scores were compared with those of well-known published conventional tests of skills that, as far as possible were equivalent or similar to those in LASS.  The results indicate significant correlations between the tests and the comparison measures, demonstrating the validity of LASS.  Horne also carried out a predictive validity study using LASS with a sample of 176 students, comprising 30 students who had been diagnosed by educational psychologists as having dyslexia, 17 students with other special educational needs and 129 students without special educational needs.  The dyslexic group scored significantly lower than the non-SEN group on five of the seven LASS tests, and the other SEN group scored significantly lower than the non-SEN group on all seven of the LASS tests used in the study.  Comparable results were found when the same groups were compared on several conventional tests.  These findings fit well with established views about dyslexia – i.e. that dyslexic students are comparatively poor on measures of literacy, phonological skills and auditory memory and these weaknesses are not due to low intelligence and provide further validation for the use of LASS in the identification of dyslexia.  When the overall profile of scores was examined, LASS was found to have correctly identified 79% of the dyslexic students as having dyslexia, compared with 63% success rate for the equivalent conventional tests and only 59% using the phonological measures alone.  These results provide convincing predictive validity for the use of LASS, which had rather greater accuracy than a mixture of conventional tests.  For further details regarding validation see Section 1.4 of the LASS 8-11 Teacher’s Manual  and Section 2.2.2 of the LASS 11-15 Teacher’s Manual.  Horne’s studies also showed that computerised tests are much less susceptible to gender bias than conventional tests; this research was reported in the international peer-reviewed research publication Journal of Computer Assisted Learning in 2007.

Research on LASS has been reported in several international conferences as well as many notable publications, including the books Dyslexia: Cognitive factors and implications for literacy (Wiley, 2002) and ICT and Special Educational Needs (Open University Press, 2004).  Among the notable professional reports on LASS is one by Alan Cowieson, Quality Improvement Officer with the Additional Support for Learning and Pupil Support Service, Department of Education, North Ayrshire Council, Scotland.  Cowieson concluded that LASS is a high cost-effective, easy-to-use system for efficient identification of dyslexia in schools. 

In addition Lucid's programs were quoted as an example of good practice in the House of Commons Education and Skills Committee Special Educational Needs Report Third Report of Session 2005-2006 Volume 2, Oral and written evidence EV 100, 101, 114 and 115.

Fact Sheet 11 contains a more extensive list of scientific publications that related to the development of the Lucid programs.