Sonically-enhanced 'drag and drop' and the use of sound in mobile computing devices

Steve Brewster, University of Glasgow

Abstract

This week's GIST talk will describe the results of two experiments in the use of sound:-

1. Sonically-enhanced drag and drop - I will describe an experiment to investigate if the addition of non-speech sounds to 'drag and drop' would increase usability. There are several problems with drag and drop that can result in the user not dropping a source icon over the target correctly. These occur because the source can visually obscure the target making it hard to see if the target is highlighted. Structured non-speech sounds were added to indicate when the source was over the target, when it had been dropped on the target and when it had not. Results from the experiment showed that subjective workload was significantly reduced, and overall preference significantly increased, without sonically-enhanced drag and drop being more annoying to use. Results also showed that time taken to do drag and drop was significantly reduced. Therefore, sonic-enhancement can significantly improve the usability of drag and drop.
2. Mobile computing devices (PDAs, HPCs etc.) have a limited amount of screen space. It is limited as the device must fit into the users hand/pocket. We wanted to see if sound could help overcome this problem. A 3Com Palm III was used. The aim of the pilot study conducted was to see if additional audio cues could improve the usability of buttons on the display and also allow the size of the buttons to be reduced but still be usable. Preliminary results indicated that for large buttons there was a decrease in mental workload when sound was added (as measured by NASA TLX), an increased user preference and an increased number of strings entered. For small buttons there was a decrease in workload across almost all workload categories, an increase in preference and an increased number of strings typed.