Concurrent Validity and Reliability of the Core Lexicon Measure as a Measure of Word Retrieval Ability in Aphasia Narratives.

Purpose General agreement exists in the literature that clinicians struggle with quantifying discourse-level performance in clinical settings. Core lexicon analysis has gained recent attention as an alternative tool that may address difficulties that clinicians face. Although previous studies have demonstrated that core lexicon measures are an efficient means of assessing discourse in persons with aphasia (PWAs), the psychometric properties of core lexicon measures have yet to be investigated. The purpose of this study was (a) to examine the concurrent validity by using microlinguistic and macrolinguistic measures and (b) to demonstrate interrater reliability without transcription by raters with minimal training. Method Eleven language samples collected from PWAs were used in this study. Concurrent validity was assessed by correlating performance on the core lexicon measure with microlinguistic and macrolinguistic measures. For interrater reliability, 4 raters used the core lexicon checklists to score audio-recorded discourse samples from 10 PWAs. Results The core lexicon measures significantly correlated with microlinguistic and macrolinguistic measures. Acceptable interrater reliability was obtained among the 4 raters. Conclusions Core lexicon analysis is potentially useful for measuring word retrieval impairments at the discourse level. It may also be a feasible solution because it reduces the amount of preparatory work for discourse assessment.