MOSAIC Threat Assessment Systems - Controversy Over MOSAIC's Validity and Usefulness

Controversy Over MOSAIC's Validity and Usefulness

In an article on the method, psychologist Hill Walker, a professor at the University of Oregon and codirector of its Institute on Violence and Destructive Behavior who had studied behavioral disorders in schoolchildren for 34 years told Wired, "There are some serious validity issues here, some reputation-ruining implications."

In a letter to the editor following publication of the article, de Becker wrote that MOSAIC for Assessment of Student Threats (MAST) “is the opposite of profiling in that it is always applied to an actual known individual, and it always explores actual behavior and circumstance,” although the original article never called it a method of profiling.

Professor Laurence Steinberg also questioned the need and use of the software for predicting violence:

In the late 1990s, the number of school-age children who died from homicide averaged around 2,500 a year. But fewer than half of 1 percent of them were killed in or around schools. Let's say, for argument's sake, that each of these incidents involved a student perpetrator. In a nation of 90,000 schools, trying to pick out the dozen or so students a year who might commit murder is like looking for a needle in a haystack the size of Kansas.

De Becker responded that MOSAIC for Assessment of Student Threats (MAST) is never applied to the general population of students, and rather just to those students who self-identify by making a threat.

There have been no peer reviewed studies published testing the reliability or validity of MOSAIC.