Exact: Summary of Research and Supporting Scientific Evidence

Lucid Exact is a suite of computerised tests designed for the assessment of literacy skills in the age range 11 to 24 years.  The Lucid Exact suite comprises standardised tests of word recognition, reading comprehension and reading speed, spelling, and writing to dictation (typing speed and handwriting speed).   These tests were selected in order to provide schools with a package of literacy measures that could be used in the assessment of students with possible examination access needs.  However, the tests can also be used for screening and monitoring the literacy attainment of groups of students. 

As with all of Lucid’s products, the tests in Lucid Exact 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.  Concurrent validation studies of Lucid Exact were carried out in 2010-11 in four different schools and involved a total of 103 students.  The results showed that all the tests in Lucid Exact correlate significantly with equivalent conventional (pen and paper or individually administered) tests that are in regular use for exam access assessments, showing that the computerised tests produces scores that are comparable with established conventional tests, and evidencing the validity of Lucid Exact.  For further details, see Lucid Fact Sheet 49 or the Section 1.5 of the Lucid Exact Administrator’s Manual.

Since there was no equivalent psychometric test of typing speed against which to validate the typing speed measure in Lucid Exact, a separate validation study was carried out by Dr Joanna Horne of the Psychology Department, University of Hull, and collaborators.  This research comprised two studies using the Exact Writing to Dictation test.  In the first study 952 students aged 11-17 years attending 19 different secondary schools hand wrote and typed passages dictated by a computer.  For both handwriting and typing, a very high correlation was found between speed calculated by the computer and that calculated by a human assessor, establishing that computerised calculation is a reliable as well as convenient and time-saving method of establishing writing speed.  In the second study, 55 students aged 13-14 were administered the Exact Writing to Dictation test together with the Hedderley Sentence Completion Test of handwriting speed.  A satisfactory level of agreement was found between the two different measures.  The study revealed that almost a third of students with slow handwriting in the computer-based task had not previously been identified as having support needs but would potentially be disadvantaged in written examinations.  This work was published in the international peer-reviewed research journal Educational and Child Psychology in 2011.


The standardisation sample for Lucid Exact comprised 1,171 students aged from 11:0 to 18:11, drawn from 17 schools across the UK, selected to give a nationally representative spread of types of school, levels of achievement and socio-economic advantage/disadvantage.  Student selection procedures conformed to international test development standards to ensure no sample bias.  Norms for ages 19:0 to 24:11 were calculated by extrapolation using recognised statistical techniques.  Reliability coefficients were also calculated and found to be high.

For further details regarding standardisation and reliability see Sections 1.4 and 1.6 of the Lucid Exact Administrator’s Manual.

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.