Quantifying Object- And Command-Oriented Interaction

In spite of previous work showing the importance of understanding users' strategies when performing tasks, i. e. the order in which users perform actions on objects using commands, HCI researchers evaluating and comparing interaction techniques remain mainly focused on performance (e. g. time, error rate). This can be explained to some extent by the difficulty to characterize such strategies. We propose metrics to quantify if an interaction technique introduces a rather object-or command-oriented task strategy, depending if users favor completing the actions on an object before moving to the next one or in contrast if they are reluctant to switch between commands. On an interactive surface, we compared Fixed Palette and Toolglass with two novel techniques that take advantage of finger identification technology, Fixed Palette using Finger Identification and Finger Palette. We evaluated our metrics with previous results on both existing techniques. With the novel techniques we found that (1) minimizing the required physical movement to switch tools does not necessarily lead to more object-oriented strategies and (2) increased cognitive load to access commands can lead to command-oriented strategies.