A quasi-experimental design with two experimental groups and one control group was used to evaluate the use of two books in the Quantitative Literacy Series, Exploring Data and Exploring Probability. Group X teachers were those who had attended a workshop on the use of the materials and were using the materials during the 1986-1987 school year. Group Y teachers were those who were trained by the Group X teachers and were using the materials during the 1986-1987 school year. Teachers of Group Z, the control group, were teaching similar classes from the same schools as teachers of Groups X and Y. A pretest was administered to all three groups in November 1986. A March Test was administered to the two experimental groups. A May Test, posttest, was administered to all three groups. In addition, teachers maintained daily logs of the amount of instructional time allocated to mathematics and the amount of instructional time allocated to the Quantitative Literacy materials. All teachers were requested to complete a questionnaire at the end of the study. A total of sixty teachers from two states, Wisconsin and Connecticut, agreed to participate in the study. A complete set of data was received from 42 teachers--7 in Group X, 25 in Group Y, and 10 in Group Z. The results indicate that using the Quantitative Literacy materials resulted in students learning approaches and techniques for describing data sets and means of computing probabilities. On the May Test, the scores of the Quantitative Literacy classes, Groups X + Y, were significantly higher than those of the control group. There were no significant differences in the student scores between Group X and Group Y. Thus, the form of training that a teacher had received did not affect student test scores. Teachers varied in the amount of time allocated to the materials and how that time was distributed. Some used the materials over an extended period of time and integrated the Quantitative Literacy materials with their regular content. Other teachers taught the materials as a unit over a relatively short period of time, one or two months. Teachers felt the materials were fairly easy to use. However, there did not seem to be significant differences in teacher beliefs that could be attributed to group membership.