MSN Search interested in Zipfian distribution

The Longtail blog covers a recent discussion with an ex-Microsoft manager - and shows that MSN Search has an interest in Zipfian distribution.

Basically, we’re talking about the longtail of search, but the ex-employee describes it in simpler terms here:

As you know, search engine query logs have a Zipfian distribution (Rank * Frequency = Constant).

Loosely speaking, if you divide the number of queries by 4, you’ll get the frequency of the most popular query, and if you divide by two you’ll get the number of queries that occurred only once over whatever time period you are measuring.

A more complex examination of Zipfian distribution puts it tus:

frequency of occurrence of some event ( P ), as a function of the rank ( i) when the rank is determined by the above frequency of occurrence, is a power-law function Pi ~ 1/ia with the exponent a close to unity (1).

It’s always interesting to see the technicalities behind search technology, and while Zipfian disitribution doesn’t have the same ring to it as Longtail, it’s interesting to see how it’s being discussed.