# Mathematical Digest

### Short Summaries of Articles about Mathematics in the Popular Press

"Drinking by Numbers," by Clive Davidson. New Scientist, 11 April, 1998, pages 36-39.

In Britain, there once was a time when a thirsty person would simply walk to the local pub for a drink. But now, people tend to look for a bar with their kind of ambience, be it a country pub, student dive, or trendy single bar. This gives brewers a rare opportunity--site the right type of pub in the right location and money will roll in. However, mistakes in placement can be very costly, so the brewer Bass Taverns has turned to artificial intelligence to guide the location decisions it makes, and we don't mean the artificial intelligence you get after one too many brews!

British demographic information is plentiful--companies can obtain data about people's earnings, spending, and domestic situation, broken down by geographical area. Bass is exploiting this information with help from a geographical information system (GIS), which not only plots this data, but also calculates distance, areas, and heights. With the right algorithms, the GIS can use the data to suggest the best locations where people meet the profile of a given bar type.

The particular GIS chosen by Bass went a bit further. Instead of just passing or failing a location based on the search criteria, the GIS can tell if a location comes close to passing. For example, if a criterion called for a location's population to be 60,000, the GIS would not exclude a location with, say, 59,500 inhabitants. This use of "fuzzy logic" makes the GIS much more flexible in chosing the best location for a particular bar type.

Bass spent nearly 300,000 pounds on its system, a small fraction of the 300 million pounds it invests in its premises each year. So, because of the GIS, don't be surprised if the kind of pub you like is right around the corner--the brewers knew you were coming.

--- Ben Stein