Metrics for Measuring Inter-item Dissimilarity in Fluency Data

This document is provided as an electronic appendix to the article “A new dissimilarity measure for finding semantic structure in category fluency data with implications for understanding memory organization in schizophrenia”. This appendix contains two parts. In the first we derive a measure of the distance between two items in a fluency list that is appropriately normalized for list-length. This measure serves as the core element of the mean cumulative frequency (mcf) dissimilarity metric described in the article. In the second part we compare and contrast the mcf metric with the prevailing Chan et al. (1993) dissimilarity metric, referred to as the dis metric here and throughout the article.