An Application of Exploratory Statistical Methods to Language Pathology

Abstract

Two simple exploratory statistical techniques, stem and leaf displays and box plots, are described and applied to the analysis of Western Aphasia Battery Cortical Quotient scores for 111 acute stroke patients. A stem and leaf display highlights the shape of a distribution of data and is useful for quickly ordering and displaying data in the form of a frequency distribution; box plots focus special attention on the tails of a distribution and are valuable for summarizing, analyzing, and comparing group data. These methods were used to determine an internal Cortical Quotient cutoff score to distinguish between normal and cognitively impaired patients. The utility of this Cortical Quotient cutoff score and the relevance of these statistical techniques to other research in communicative disorders are discussed.