Information Visualizations for Supporting Knowledge Acquisition - The Impact of Dimensionality and Color Coding

So far, information visualizations, i.e., graphical representations of huge amounts of abstract data which do not have a natural visual representation, have mainly been used to support information-retrieval tasks. In this paper we investigate whether information visualizations are also suitable to foster tasks that focus on knowledge acquisition or learning. In addition, we address the issue of how information visualizations have to be designed to be efficient learning tools. We conducted an experimental study which provided evidence that information visualizations can foster knowledge acquisition and that 2D-information visualizations are better suited for knowledge acquisition than 3D-ones. In addition, we found slight performance improvements due to using color to code information. Technological innovation allows storing fast growing quantities of information. Accordingly, it has become increasingly important to develop efficient methods to structure large and complex information sets. Recently, there have been several attempts to tackle this challenge by using information visualizations, i.e., graphical representations of large amounts of abstract data which do not have a natural visual representation (Wiss, Carr, & Jonsson, 1998). For instance, information visualizations have been used to display abstract data like document collections or text-based information contents in the WWW. So far, information visualizations have mainly been investigated with regard to technical issues and in the context of information-retrieval tasks – where they proved to be very useful to improve users’ ability to use information. However, it is not clear whether information visualizations can also foster knowledge acquisition or learning. Additionally, little is known about the cognitive processes involved in, and maybe supported by the use of information visualizations as learning tools. Therefore, the aim of our empirical study was to investigate to what extent multidimensional information visualizations are superior compared to a non-spatial representation when the task is to memorize a data set and to acquire an understanding of the relationships embedded within this set. Moreover, we were interested in the design of information visualizations for learning. Particularly, we investigated experimentally whether information visualizations should be two-dimensional or whether a third spatial dimension may be helpful for knowledge acquisition. Finally, the question is addressed whether knowledge acquisition with spatial information visualizations can be further enhanced by using color coding to represent attributes of data. Figure 1 shows a simplified sketch of the type of spatial information visualization used in the empirical study presented in this paper. In this sketch, three attributes of four information units A, B, C, and D are represented by means of three spatial dimensions. Figure 1: Simplified sketch of a 3D-information visualization. Information units pool those parts of data sets that belong together. The units can be described by their values on numerous different attributes. Typically, only a subset of these attributes can be represented spatially. Thus, other attributes of the information units may be represented textually or by other codes (e.g., color coding). What is the Pedagogical Potential of Information Visualizations? There are different cognitive theories arguing that information visualizations may be efficient tools to enhance the acquisition of knowledge on large and abstract data sets, attribute 2