Siri, the new voice control feature on the iPhone 4S, accounts for about a quarter of all searches on Wolfram Alpha. The online search service takes a different approach to fact finding by referencing its own database instead of scouring the Internet for results, and has proven popular with students and researchers.

A quarter of Wolfram Alpha searches come from Siri

Stephen Wolfram is using Wolfram Alpha to further research into semantics, which is a great fit for Siri since the feature attempts to sort out what you mean by listening to the words you speak instead of forcing you to use a limited set of predetermined words.

Now Dr. Wolfram is ready to push his data search service to a new level with the introduction of Wolfram Alpha Pro, according to the New York Times. The Pro version of Wolfram Alpha can interact with data you give it; for example, dragging a table of numbers into Wolfram Alpha Pro will give you color coded bar charts.

The Pro service is scheduled to launch on February 8 and will cost US$4.99 a month, or $2.99 a month for students.

The Wolfram Alpha team has grown to more than 200 employees thanks to the service’s popularity. Thanks in part to the popularity of the iPhone, there’s a good chance the search service will continue to grow, too.