In this talk I will discuss some of the difficulties of using telephone-based systems and in particular navigation problems. More services are becoming available over the telephone but usability must be ensured otherwise they will not be used. A review of previous work in the area shows that navigation is a big problem and it is one that cannot be easily fixed with speech messages. Initial studies showed that structured earcons could give navigation cues. However, this earlier work had many drawbacks: It used high quality sounds, it did not test memorability over time and the method used to represent the hierarchy was limited
I will discuss two sets of experiments to look at the problems. The first set considered the problems of lower audio quality over the telephone, memorability and training. Lower quality did have an affect on the usability of earcons but it was fixed by redesign of the sounds. The earcons proved to be easily remembered over time, which is important if you are not using the telephone service frequently. Different training techniques gave varying rates of recall of the sounds. Personal training by the experimenter gave the best results with textual training giving the worst.
The last experiment, as part of Adrian Capriotti's honours project, has looked at alternative methods for presenting hierarchies. Until now this has been done with hierarchical earcons. This causes difficulties because it is hard to create deep and wide structures. Adrian has been investigating compound earcons to do the same job. His 'hot off the press' results will presented if we get them analysed in time.
For more information about this talk please contact stephen@dcs.gla.ac.uk.