Reports an error in “What item response theory can tell us about the complex span tasks” by Christopher Draheim, Tyler L. Harrison, Susan E. Embretson and Randall W. Engle (Psychological Assessment, 2018[Jan], Vol 30[1], 116-129). In the article “What Item Response Theory Can Tell Us About the Complex Span Tasks,” by Christopher Draheim, Tyler L. Harrison, Susan E. Embretson, and Randall W. Engle (Psychological Assessment, 2018, Vol. 30, No. 1, pp. 116–129, http://dx.doi.org/10.1037/pas0000444). In the article, a programming error in the operation span task in Study 2 resulted in set size 8 being administered instead of set size 9. Set sizes 3–7 were administered as intended, but set size 8 was administered twice in each block instead of one instance of set size 8 and one instance of set size 9 per block. As such, all references to set size 9 should be interpreted as an additional administration of set size 8. This error has some minor implications for the results and conclusions of Study 2 whereby it can no longer be confidently asserted that an operation span task with set sizes 8 and 9 added would be any less suitable for higher ability subjects than the rotation and symmetry span tasks. However, the error has no bearing on the argument that the standard administration of the operation span (set sizes 3–7) is lacking and that the addition of larger set sizes to the operation span vastly improves its utility for testing higher ability individuals. (The following abstract of the original article appeared in record 2017-10875-001.) Working memory capacity is an important construct in psychology because of its relationship with many higher-order cognitive abilities and psychopathologies. Working memory capacity is often measured using a type of paradigm known as complex span. Some recent work has focused on shortening the administration time of the complex span tasks, resulting in different versions of these tasks being used (Foster et al., 2015; Oswald, McAbee, Redick, & Hambrick, 2015). Variations in the complex span tasks, such as the number of set sizes, can lead to varying power to discriminate individuals at different ability levels. Thus, research findings may be inconsistent across populations due to differing appropriateness for the ability levels. The present study uses a combination of item response theory and correlational analyses to better understand the psychometric properties of the operation span, symmetry span, and rotation span. The findings show that the typical administration of these tasks, particularly the operation span, is not suitable for above average ability samples (Study 1; n = 573). When larger set sizes are added to the tasks (Study 2; n = 351), predictive validity and discriminability is improved for all complex span tasks, however the operation span is still inferior to the spatial tasks. The authors make several conclusions about which tasks and set sizes should be used depending on the intended population, and further suggest avoiding the standard-length operation span for average or higher ability populations. (PsycINFO Database Record (c) 2018 APA, all rights reserved)