Sissel Guttormsen Schär

Alternative tools for tangible interaction: a usability evaluation

In this work we compare an in-house designed tangible user interface (TUI) with three alternative single-user tools through an empirical investigation. These three alternative tools are a 3D physical, a 2D cardboard, and a mathematical tool. We expected the 3D physical to perform best, followed by the TUI, the 2D cardboard, and the mathematical tool. A pilot study was first carried out, the results of which were used to design a major experiment. Participants solved the same positioning problem, each using one of the four tools. The mathematical tool was not used in the experiment. In the experiment, trial time, number of user operations, learning effect in both, and user satisfaction were measured. The TUI significantly outperformed the 2D cardboard tool. However, there was no significant difference between the TUI and the 3D physical tool. This justifies the value of researching TUI systems and carrying out usability studies with such systems.

The Effect of the Interface on Learning Style in a Simulation-Based Learning Situation

The applicability of a cognitive theory of implicit and explicit learning to computer-aided learning was tested with a two-factor experimental design. The interface factor tested whether a direct manipulation and a command-based interface can induce the users to implicit or explicit learning, respectively. The complexity factor tested whether the benefit of using one of the interfaces (i.e., learning modes) depends on the task complexity (high or low). According to the theory, the success of using one of the learning modes depends on characteristics of the tasks. The application of the theory to computer-aided learning would be to characterize the learning task and then choose the interface that best fits the task requirements. The ability of the user interfaces to induce the learning modes was supported by the results. The explicit learning mode observed in the users of the command-based interface resulted in better performance for both complexity conditions. Although the users of the direct manipulation...