California's College of the Canyons has used the four Mathematics Diagnostic Testing Project (MDTP) tests to assess students' abilities in basic and college math since spring 1989. These four reports dated June 1993, July 1993, May 1994, and June 1994 examine the predictive validity of the MDTP tests and the cut scores used to place students. The first report compares outcomes for students in fall 1991 and fall 1992 who followed placement advice to those who did not, finding that for MDTP tests 1, 2, and 4, a higher percentage of students who followed placement advice were likely to receive satisfactory grades than those not following advice. The second and third reports examine the predictive validity of the MDTP tests in studies conducted July 1993 and May 1994, with evidence from the 1994 analysis indicating that the MDTP tests exceeded the minimal standards for the predictive validity of placement instruments. This report also recommends that MDTP versions 1, 2, and 4 be used to direct students into mathematics classes. The fourth report examines the best possible cut scores for the placement tests by using scatter plots to separate successful versus unsuccessful course outcomes, finding the current scores reasonable, and recommending that sub-scores not be used in placement but that their results be given to students and faculty as feedback. (KP)