Revisiting the Speed Accuracy Tradeoff: A Study of Informal Note Taking Using Mobile Information Technologies

Mobile information technologies are theoretically well suited to digitally accommodate the informal note taking task wherewith the notes often recorded quickly and under less than ideal circumstances. Unfortunately, user adoption of mobile support for informal note taking has been hindered in large part by slow text entry techniques. Building on research confirming people's ability to read erroneous text and effectively use incomplete external retrieval cues, this dissertation investigated the effects of two modifications to Graffiti-based text entry with the goal of overcoming the barriers associated with current text entry solutions: disabling text correction and disabling visual feedback. As expected, both modifications improved text entry speed but also resulted in more errors in the resulting text which hindered the users' ability to recognize the words they had recorded. To address this decrease in recognizability, a multi-approach note enhancement mechanism was introduced. When this algorithm was applied to a set of particularly challenging erroneous notes, study participants were able to correctly recognize 56% more of the words in the notes. In a formal evaluation study with 75 participants, the proposed approach of discouraging user-initiated error correction during note taking, enhancing the resulting erroneous notes, and facilitating recall with enhanced alternative lists, was confirmed to increase the note taking speed by 47% without any negative impact on the participants' ability to recall important details about the scenarios which prompted the note taking activities. This research highlighted the importance of shifting the focus from accuracy to recallability when examining the overall efficacy of informal notes. With some easily implemented modifications to existing text entry techniques, combined with a note enhancement algorithm which leverages information about the errors users make and the types of errors users are more likely to overcome, a significant improvement in user performance was achieved. These results have important implications for how mobile technologies are designed to support both informal note taking and text entry in general