Speech and Hearing Science Commons^™

Psychometric Evaluation Of Lexical Diversity Indices: Assessing Length Effects, Gerasimos Fergadiotis, Heather Harris Wright, Samuel B. Green

Speech and Hearing Sciences Faculty Publications and Presentations

Purpose—Several novel techniques have been developed recently to assess the breadth of speaker’s vocabulary exhibited in a language sample. The specific aim of this study was to increase our understanding of the validity of the scores generated by different lexical diversity (LD) estimation techniques. Four techniques were explored: D, Maas, Measure of Textual Lexical Diversity (MTLD), and the Moving Average Type Token Ratio (MATTR).

Method—Four LD indices were estimated for language samples on four discourse tasks (procedures, eventcasts, story retell, and recounts) from 442 neurologically intact adults. The resulting data were analyzed using structural equation modeling.

Results—The scores on the …

Effects Of Truncation On Language Sample Analysis In Aphasia, Gerasimos Fergadiotis, Heather Harris Wright

Speech and Hearing Sciences Faculty Publications and Presentations

The goal of this study is to determine if the length of a language sample elicited from a person with aphasia (PWA) is of consequence when making inferences about the patient's functional language ability. When conducting a language sample analysis, a sample representing a snapshot in time is used to make inferences about an individual's language capacity in general. However, current findings are inconclusive regarding the ideal length of the language sample necessary to draw valid conclusions about patients (e.g. Heilman, Nockerts, & Miller, 2010).