Data mining not yet ready to take on terror cells.

Despite advances in the science behind data mining--the use of software programs to sift through reams of data to find suspicious patterns--the practice may not be ready for full-scale use in homeland security and terrorist hunting, according to a leading expert.

Chief among the limitations is a lack of real-world examples to create the profiles that suggest dangerous activity, according to Bhavani Thuraisingham, director of the information and data management program at the National Science Foundation.

"To apply data mining, you have to learn from the past. There are not enough real training examples, so we have to come up with hypothetical examples," she said a recent conference. "The question is, can you build a model with only 10 good examples? The answer is usually no."

Another limitation cited by Thuraisingham is the complexity of building real-time mining programs that can collate massive amounts of data under time constraints. "Right now, we need humans in the loop to examine the results. Automatically, the system can not say, 'This is a false positive.'"

Real-time data mining currently is being used for credit and calling card fraud detection, but Thuraisingham said in those cases models can be crafted ahead of time, and "we still don't have a way to build models in real-time."

Other uses for data mining may include using the system to monitor data from biological sensors, medical databases and to protect networks from hackers. "This is a very new area. Before 9/11, not many people were talking about data mining for counter terrorism," she added.

Hovering over the discussion was the issue of privacy violations. Last September, Congress shut down a Pentagon program called Total Information Awareness citing privacy concerns. Politicians from both sides of the aisle raised fears that the project was collecting too much personal data in its attempt to find terrorists.

The General Accounting Office released a report last month noting that the Defense Department had the largest number of data mining efforts, primarily aimed at managing human resources. Defense was also the most frequent user of data mining for analyzing intelligence and detecting terrorist activities.

The system of using personal and demographic information to profile possible terrorists raises the hackles of civil right lawyers and privacy advocates, but Thuraisingham said encryption technology may be employed to lessen the exposure and avoid misuses of personal information.

In balancing privacy against effective data mining, Thuraisingham said she was worried "that we might try to do both and fail at both ... We can't get hung up on privacy while we're doing this important work."