“…The CPT has also been found to have adequate test-retest reliability across a range of time spans (time elapsed = 4.8 months, r s = .65 to .74; time elapsed = one week, rs = .74 to .87; time elapsed = 90 minutes, rs = .70 to .87) and adequate split-half reliability ( r s = .67 to .92) comparing performance on the 1 st and 4 th quarter blocks of the task to performance on the 2 nd and 3 rd blocks of the task (Halperin, Sharma, Greenblatt, & Schwartz, 1991; Leark, Wallace, & Fitzgerald, 2004). However, despite the adequate psychometric properties of the test and almost ubiquitous findings of abnormal performance by children with ADHD on CPTs, its utility as a primary diagnostic tool is weak (Nigg, Hinshaw, & Halperin, 1996) and its negative predictive power is low (Grodzinsky & Barkley, 1999).…”