| With the rapid growth in the amount and complexity of information and increased need to make-sense of this information, it seems pertinent to find improved ways to support human-information exploration. This dissertation is about facilitating people's exploration of information. It examines how to design computationally-based representational media of information. These media are not only dynamic, but also adaptive to the structure and context of activities, such as visualizing, analyzing, interpreting, meaning-making, decision-making, planning, problem-solving, and learning. Two important components of these media are visual representations and interaction. Visual representations are collections of graphical symbols organized to emphasize the relational, structural, and other properties of the represented information (e.g., structures, objects, concepts, ideas, or problems). These representations are intended to be supportive of users' epistemic or knowledge-based activities by making information perceptually and cognitively easier to explore. Interaction extends the supportive power of representations and is defined as the actions users perform on the representations and the reactions given in response to these actions. It is interaction which renders representations responsive and adaptive to users' contextual, cognitive, and perceptual requirements during information exploration. A visual cognitive tool is any external computer-based application which maintains and displays visual representations and allows users to act upon them to perform knowledge-based activities.;Keywords. Human-information interaction; Interaction Design; Design frameworks; Cognitive tools; Visualization tools; Mathematics learning; Usability studies.;This dissertation focuses on interaction and investigates the role of frameworks and taxonomies in assisting the design of the interactive features of visual cognitive tools. Frameworks and taxonomies play an important role in design, as they organize ideas and techniques, help with the analysis and comparison of these ideas, guide design, and promote innovation. The application context of this dissertation centers on the design of visual learning environments, a subset of cognitive tools, with emphasis on supporting users' thinking about, reasoning with, and learning of mathematical concepts and structures. The main contributions of this dissertation can be divided along two levels: conceptual and empirical. At the conceptual level, we have developed five frameworks: (1) interactivity of visual representations; (2) fitness of interaction; (3) presentation of feedback; (4) characterization of visual cognitive tools; and (5) navigation within information spaces. At the empirical level, we have designed, implemented, and tested numerous tools and visuo-interactive techniques. Results from our empirical studies have been analyzed and organized into design recommendations. The findings of this research can have implications for the design of human-computer interfaces of all interactive information-rich environments. |
