The Cognitive Estimation Test (CET): psychometric limitations in neurorehabilitation populations.

The Cognitive Estimation Test (CET), which purportedly assesses aspects of executive functioning, consists of answering questions that require deductive reasoning. This paper explored the CET's psychometric properties in neurorehabilitation samples, including its reliability and strength of association with tests involving varying levels of executive skill. Among 112 patients (age = 65.3 years, SD = 12.5) with various neurological impairments, CET performance had limited reliability and was moderately correlated with nearly all cognitive tests examined, regardless of their executive demands. These findings highlight the poor divergent validity of the CET and raise questions of its utility in cognitive assessment.