Card sorting for cartographic research and practice

In this article we describe the potential utility of the card sorting method for structuring and refining large map symbol sets. Simply defined, card sorting requires that participants organize a set of items (i.e., cards) into categories according to some characteristic(s) of the cards (i.e., the sorting criterion). Card sorting has been proposed as a method for delineating categories by researchers and practitioners in a variety of disciplines due to its ability to identify and explicate real or perceived structures in an information space; despite this, there is little reported application of card sorting within cartography. To facilitate application of card sorting to cartographic problems, we offer a framework that prescribes the appropriate experimental design settings for the method based on the stage in the design process and the goals of the study. We then demonstrate the utility of card sorting for cartography by describing a closed sorting study we conducted on the ANSI INCITS 415-2006 emergency mapping symbol standard. Our approach helped us identify several barriers to using the symbol standard, including areas of conceptual overlap among the categories included in the standard, potentially missing categories from the standard, and individual symbols in the standard that are consistently misclassified