March 28th, 2008 | Published in Google Research
A couple of years ago, a few of us got together and decided to build Goog411. It would be a free phone service that users could call to connect to any business in the US, or simply to browse through a list of businesses such as "bookstores" in a given city. Everything would be fully automated, with no operator in the background, just a speech recognition system to converse with the user, and Google Maps to execute the business search.
We knew that speech recognition is not a solved problem; there would be users for whom the system wouldn't work well, and queries that would be harder to recognize than others. But we got big assets through hosting the service: we could iterate as often as we wanted on any component of the system, we'd have access to all the data, and we could measure whatever seemed relevant to callers. So we built Goog411, started taking some traffic, defining metrics, and iterated many, many times.
We learned a few interesting things in the process (see our ICASSP paper). For example, we discovered that databases with lists of business names are almost useless to train a language model for how users answer the question "What business name or category?"; aggregated web query logs from Google Maps yield far better performance. And we found the speech data we collect through our own service is almost as useful to model new queries as the web data, even though we have orders of magnitude less of it. After all, you may type "real estate" in Google Maps to glance at a few properties, but would you ask for it over the phone while driving your car?
Today Goog411 has grown from an experiment into a product, and we're working on expanding the service to Canada. As calls flow through the system, our focus is still on making the best use of the increasing data, defining metrics that best correlate to the user's experience, and taking advantage of the computer resources and data sources available within Google.
Maybe our most rewarding experience so far has been to see our traffic grow, and to see repeat callers succeed more and more often with the system. Have you tried it already? Just call 1-800-GOOG-411, and don't hesitate to send us feedback!