A Quick VUI Checklist 
In this issue of the VUI View, I offer a basic checklist of must-do tasks that should be accomplished before a voice application is released for general public use. The checklist, if used systematically, should help you pinpoint any loose Voice Site settings that, left unchecked, could result in a flawed Voice User Interface (VUI).
Error destination
Voice applications that use transaction or data pages should always have an error page associated with those pages to ensure that something user-friendly happens when an error occurs. You can associate an error page with a transaction or data page by clicking on the "Advanced Options" tab for the page and then selecting the corresponding error page from the "Error Destination" drop down menu.
Email debugging
When things go wrong, it is always better to find out about it sooner than later. The "email debugging" feature is an easy and built-in tool which can be set to notify you when an error occurs during the processing of a data or transaction page. Make certain that you always specify the email address where these error messages should be sent. For signaling errors, select the "On error only" option.
Initial prompts
Callers are typically on hold for a few seconds as data and transaction pages are executed. To mitigate the wait time perceived by the caller, specify an "initial prompt". This prompt will play while the data page operations are executed or the content of the transaction page is fetched. See Transaction Page Tips and Tricks for more information.
Wait prompt
If the "Initial prompts" described above complete and two seconds pass without completion of data or transaction page operations, the wait prompt is played in a loop until a remote server responds. Make sure that playing this prompt as a loop is not going to irritate the caller. Safe content for this type of prompt is on-hold music or sound indicating that the call is still alive (for instance, the sound of a computer keyboard).
Final no-match
The only thing more irritating than a system that does not understand what you are saying is a system that does something seemingly random once it decides that it will no longer try to understand your answers. Make sure that every final no-match in your Voice Site is pointed to a Voice Page that makes for a helpful next step. For more information, review "Know what to do next".
Final no-input
Similarly, make sure that every final no-input in your Voice Site is pointed to a Voice Page that results in a helpful next step.
Re-prompt
Pay specific attention to the flow of prompts when a no-input or no-match occurs. If a Question Page opens with the following prompt: "Great! Now, how many cigarettes do you smoke each day?" and the caller says nothing in response, a smart re-prompt would be something like, "Sorry, I didn't hear you. Please say a number between 1 and 100. How many cigarettes do you smoke each day?" A not so smart re-prompt would say, "Sorry, I didn't hear you. Please say a number between 1 and 100. Great! Now how many cigarettes do you smoke each day?" See "Use smart re-prompting" for more information."
Confirmation
The ability to confirm with the caller what he/she said is a very useful, and often indispensable device, for ensuring quality and accuracy. This device is available with two types of Voice Pages, Question Pages and Voicemail Pages. The default setting ("off" for Question Pages and "on" for Voicemail Pages) on confirmation for Question Pages should be overridden only with pages where the information collected from the caller is crucial to executing a next step (bank account number, social security, full name, address, etc.).
Barge-in settings
Barge-in -- the ability to interrupt a system prompt with voice or DTMF input -- is useful for experienced callers and should be turned on in most situations. But there are situations where you will want to turn the barge-in off, such as during the very first opening prompt, or when crucial information is being communicated by the system to the caller.
Call scenario settings
Call transfer and Call queue pages have a section called "Call Scenarios" that allows you to specify what action to execute depending on whether the result of a call transfer attempt was a no answer, a busy line, timeout on transfer, or call completion. The default for all scenarios except call completion is "Home Page". The default action for call completion is "End the Call".
Stray TTS prompts
There is really no valid reason to use Text To Speech for static prompts that you use to instruct the caller on what to say or do. When you are going over your Voice Site, make sure you note any prompts that are still in TTS and that you take steps to ensure that a recorded version of those prompts is ready prior to deployment.
The table below summarizes the 12 areas covered above. Use this table to determine which Voice Pages apply to for a particular task, the default values for settings pertaining to those areas, and how to change the settings in the Voice Page.
Below is a table that should be useful for quickly determining which areas need to be examined for each type of Voice Page. When I go over a Voice Site to make sure that all settings are correct, I click on each Voice Page and I go over the areas pertaining to that Voice Page, one by one. For instance, if the Voice Page I am examining is a Voicemail Page, I make sure that I hit all the areas that pertain to a Voicemail Page: Final no-match, Final no-input, Re-prompt, Confirmation, Barge-in, and Stray TTS prompts.
To help you document your work, you should print several copies of the following PDF, one copy for each Voice Page you plan to examine, and check the appropriate boxes as you go through your checklists.
VUI Checklist PDF, 55KB
Angel.com's VUI experts will be happy to examine your Voice Sites and provide a review based on the above checklist. The fee is $100.00 for Voice Sites with 50 Voice Pages or less. For larger sites, please contact us at info@angel.com for an estimate.
