Top 5 VUI Dialog Design Guidelines for Handling Errors - #3 of 5
Posted by: eolvera, in Usability, Dialog Design
Continuing the series, here’s the third guideline for handling errors when designing Voice User Interfaces:
Guideline #3: Avoid the use of delayed help
This is a controversial guideline in which VUI designers don’t seem to have found a consensus on whether the benefits justify the difficulty of implementing it properly.
The idea of “delayed help” (additional information played following an initial prompt after a predetermined amount of time) was developed in order to serve both expert and novice users at the same time: the former could respond and move on after listening to the initial prompt, while the later could get a little extra piece of information that would help them choose the right option on the first attempt.
Unfortunately most pilot analysis results have shown that even though this approach might have a place on the Design toolbox, most of the time the risks and implementation complexity associated with the pausing denies any potential benefits.
The top two issues are related to the fact that the time of the pause in between prompts is very hard to determine since there are multiple factors affecting it such as context, state of mind, complexity of initial prompt (since users need to understand the choices they just heard and make a decision), caller base demographics, etc.
Aside from trial and error there isn’t an easy way to determine what the ideal length should be, and the frequent turn taking issues that arise once an error occurs (caller takes too long to respond so they speak while the delayed help is being played, which causes a barge-in and tends to lead callers to stop talking in the middle of their response).
Other articles on this series: [1], [2], [4], [5] and [extra]