An Examination of Domain-Specificity Differences in Complex Span Tasks through Item Response Theory

Abstract

Working memory (WM) is the ability to maintain a goal in mind while manipulating information in the face of concurrent action (Baddeley & Hitch, 1974). While complex span tasks have been widely used to measure WM, debate still exists regarding the extent to which complex span tasks vary in reliability and construct validity in terms of capturing the domain general variance of WM. Item response theory (IRT), a largely unexplored approach in this vein of work, could help further understand such potential variation. Two spatial and two verbal complex span tasks were examined using IRT. The findings show that spatial tasks generally surpass verbal tasks because they have (1) more variety in item difficulty and (2) better item discrimination. The results provide evidence for future work in making improvements upon current administrations and selections of complex span tasks.