Voice User Interface Design VUI

It seems one of the most frequent questions that come up when designing a new user interface is “how many options should appear on any given menu?” which depending on the answer is almost always followed by “how many levels down should the system have?”

And believe me, neither one has an easy or absolute response. As witnessed by some of the heated debates on the VUIDs list, the old standing guideline of “five options or less” was recently put to the test when Patrick Commarford and James Lewis from IBM published the article entitled “A Comparison of Broad Verses Deep Auditory Menu Structure” where the results seem to indicate that when comparing broad vs. deep menu designs, giving callers a single menu with many options (providing touchtone fallback) yields better results than using fewer options supported by submenus.

Aside from all the points, concerns, comments and objections raised by both the authors, the VUI community and other blogs, in my opinion I think it’s going to be really hard to reach a consensus if the main focus of the discussion if to agree on whether *5* is the right number of choices or not. The problem I see with trying to find that ‘ideal’ number is that a number by itself doesn’t mean anything. In this case, I think the devil is in the *context*.

In other words, any attempt to generalize what a good design should look like without taking into consideration the context of the application is not very responsible. We all know there are many factors that need to be taken into account when designing any system: caller’s age, demographics, type of application, caller’s objectives, business goals, etc.

Furthermore, when evaluating possible menu choices, the frequency with which each choice is needed and used by callers should not only drive their position within the menu but also the decision of whether or not the option should be in that menu in the first place (for example, if the top 3 choices on a menu are used 45%, 31% and 20% of the time respectively, then adding one more choices that’s only used 1% of the time should not be considered – in fact those calls are likely to be better handled by agents in the first place).
When all those factors are added to the mix, then an appropriate design *strategy* can be conceived.

For example, when thinking about the context of an application, imagine a system asking callers to choose a bird species – “And which type of bird is circling around you: dendrocygna, gelochelidon, herpethotheres, or tachycineta?”. In that scenario, unless you’re a birdwatcher, you’re likely to be overwhelmed even after hearing only 3 choices. The counterpart of course would be to ask for something so common and known that the number of choices in itself wouldn’t make a difference – “And which planet are you calling from: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune or Pluto?”

I definitively believe the industry should strive to find more answers to long standing questions, particularly when those responses can be backed up by real world data, but in this case, I think that unfortunately the answer to the question whether to go broad or deep on menus still is… it depends.

I recently ran across a series of posts and a SpeechTEK magazine article about a new service currently in Private Beta called Fonolo.

The premise is definitively very interesting. What this Canadian start-up is attempting to do is to replicate the concept of bookmarking and deep linking (process of linking pages in the lower levels of a Web site from a home page - or other pages - to help search engines index them) so common these days on the web. What this means for a phone user is that they don’t need to get to the application’s “home page” (aka Main Menu) every time to then have to traverse the phone tree to reach a specific destination…

According to their founder’s pitch, the way it works is that you “bookmark” a spot deep inside a telephone’s system tree. To do this, you go to the Fonolo’s website, find the Company you need, review a transcription of their menu structure, find the spot you need and click on it. By doing that, they call the company for you, navigate the menu up to that specific spot and call you back so you can continue your transaction from that point on.

How do they know what systems look like? Well, as noted in the VoIP weblog, they seem to be using a combination of voice recognition and human editors to generate “maps” of the interactive voice response system.

Aside from the obvious privacy concerns a service like this might raise, the hottest one in my opinion is the service they refer to as “Intelligent Call History”. Since in reality all your calls start from their home page, they are attempting to become something like a Google of sorts for “phone sites”. What I mean by that is that they would keep track of all the interactions you’ve had with a certain company (regardless of the phone you used), along with the actual recordings of those conversations!

In the web world, we’re all familiar with how certain companies keep logs that track your web habits which could then be linked to your IP address. The biggest difference to me is that they mostly keep track of where you’ve been and where you’re going, but not of what’s happening when you are there… and in this case, since you’re using them as a bridge to connect to a Company, how can you be sure those recordings (which may contain account numbers, PINs, etc.) are kept safe and out of anybody’s reach?

Presumably the advantage of something like this is that in case of a dispute, you could play back a recording from the actual conversation and prove a certain transaction happened. But is this benefit really worth the risk? Particularly when it is known that once it becomes available to the public, it will be ad-supported.

On the other hand, they have also expressed that their ultimate goal is to craft partnerships with those companies Fonolo has mapped so that those companies can notify them “when they change or update their IVR” to the point where they hope companies will indeed send transcripts of their IVRs so they don’t have to be mapped anymore

Again, I definitively like the idea of empowering users and allowing them to accomplish their task in the most efficient way, but I think a system like this would be a much better fit for an actual device feature (similar to the GOOG411 dedicated button now present in some phones) - which you could turn on at the beginning of a call and stop once you reach the spot you want to “bookmark” so that in the future your phone would simply repeat the steps you followed and get you to that same spot. And of course, rather than finding more ways to patch user-unfriendly architectures, companies should be looking at fixing the root problem, which in the short term can be somewhat addressed via the deployment of more SayAnything/ SpeakFreely-type menus so callers can say what it is they need right at the beginning of an application…