Development of Lucid Recall

Test development

The choice of measures to include in Lucid Recall was guided by the multiple component model of working memory described above (Baddeley, 2000; Baddeley & Hitch, 1974). One core test (Word Recall) was included to assess the phonological loop. A large body of research has identified immediate serial recall as a paradigm that is suitable to assess phonological loop functioning. Another core test (Pattern Recall) was included to assess the visuo-spatial sketchpad. This provides a measure of visual rather than spatial short-term memory (see also Della Sala, Gray, Baddeley, & Wilson; 1997; Della Sala, Gray, Baddeley, Allamano & Wilson, 1999). The final core test (Counting Recall) was included to assess the central executive component of working memory. This is a variant of a complex span task in which participants have to simultaneously store and process information (e.g. Case, Kurland & Goldberg, 1982). It is assumed that such tasks involve both the storage and central executive components of working memory.

A description of each test is provided in Section 2.1. Each of the three core tests is adaptive, with progress through each test and point of discontinuation being determined by cumulative performance. More able students will progress through the test quicker and reach higher levels. Less able students will progress more slowly and generally avoid the unnecessary frustration of levels that are much too difficult for them. This reduces assessment time and helps to maintain the test-taker’s motivation regardless of ability.

Types of results

Normative results in standard score and centile score form are incorporated into the Lucid Recall program for each of the three core measures. The norms are provided in 6-month age bands from 7:0 to 16:11, together with confidence intervals and age equivalents. These different types of results are explained in Chapter 3.

An overall measure of general working memory functioning, called Working Memory Composite, was obtained by combining the scores of the three subtests with appropriate weighting to allow for differential item length.

A measure of speed of processing was derived from the Counting Recall test by means of an algorithm that reflects the average time taken to count each item, adjusted for counting accuracy. This derived measure is referred to as Working Memory Processing Speed.

For each of the three core tests comparative results are provided for Memory Span (based on the maximum difficulty level reached in each subtest) in three bands: ‘low’, ‘average’ and ‘high’, where the ‘average’ range represents the modal score range for that age group, with ‘low’ and ‘high’ covering the score range below and above this respectively. Memory span is a measure of the number of items of information that the person can hold in memory at any given time.

Comparative results are also provided for Average Time on each of the three tests. This is categorized as ‘fast’ (less than one standard deviation below the mean time per item of the standardisation sample), ‘average’ (between one SD below and one SD above the mean time per item of the standardisation sample), and ‘slow’ (more than one SD above the mean time per item of the standardisation sample).

The reason why standard scores for memory span and average time have not been provided is explained in Section 1.3.3.