This data collection contains the data from the fourth of four studies conducted on the associated ESRC grant (data from the other studies will be made available as separate datasets in ReShare). The aim of this study was to build on the work done in the three previous experiments on the grant that looked, in turn, at the development in children of primary memory, processing speed, and secondary memory. Measures taken from these earlier studies were used in this work to determine which of these factors underpinned working memory development in children, and the extent to which they mediated the relationship between working memory and academic attainment. A total of 218 children in school years 2 and 3 completed a range of experimental measures tapping primary memory, various aspects of processing speed, and secondary memory. Experimental measures of short-term memory ('simple span') and working memory ('complex span') were also given, as were a standardised test of mathematics [Numerical Operations subtest of the WIAT-II UK], a novel measure of reading comprehension, and a standardised test of classroom behaviour [Conners’ 3 Teacher Short Form]
