We examined the structure of the new "Block Patterns" (BP) test from the Shipley Institute of Living Scale-Second Edition in a sample of Jamaican young adults. To date, very little has been published on the properties of this subtest's items and scores. The BP test is similar in design to the Block Design subtest found in many cognitive ability assessments but uses a matching format that minimizes the need for excess materials and time. We analyzed the BP items using item response theory (IRT) methods. Although designed to measure a single construct, the analyses from this study found that the BP subtest is likely measuring more than a single construct, which confounds the interpretation of the instrument's scores. Before the subtest is used clinically, more research should be done to purposefully investigate the effects of ancillary variables on its scores.