LASS: Summary of Research and Supporting Scientific Evidence

Lucid Ability comprises two computerised tests designed for the assessment of verbal and non-verbal reasoning skills in the age range 4–16 years.

As with all of Lucid’s products, the tests in Lucid Ability 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.  Standardisation was carried involved a total of 4223 students aged 4-16 years selected to give a nationally representative sample.  For further details regarding standardisation, see Section 2.1 of the Lucid Ability Administrator’s Manual.

Concurrent validation of Lucid Ability was carried out using a total of 215 children in several schools in different parts of the UK, covering a range of socio-economic groups.  The results showed statistically significant validity coefficients with the British picture Vocabulary Scale (BPS), the NFER-Nelson Verbal Reasoning Test, the British Ability Scales, and the matrix Analogies test, indicating satisfactory validity of the various components of the suite.  For further details regarding validation, see Section 2.2 of the Lucid Ability Administrator’s Manual.

The test-retest reliability of Lucid Ability was carried out over a four-week period with a sample of 98 students aged 11 to 16.  The results indicated satisfactory reliability.  Another form of reliability, generally known as ‘internal consistency’, indicates the extent to which the items within each test are measuring the same ability or set of abilities.  For Lucid Ability internal consistency been calculated at 0.96 for verbal reasoning and 0.91 for nonverbal reasoning, which is very high.  For further details regarding reliability, see Section 2.3 of the Lucid Ability Administrator’s Manual.

Research on the validity and reliability of Lucid Ability study was published in the international peer reviewed journal Educational and Child Psychology in 2001 [Vol 18, pp. 58-74 ].    

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.