The purpose of this study was to determine if there was a statistically significant difference in the reading achievement of students enrolled in the reading laboratory approach to teaching reading when compared to those students enrolled in a regular self-contained classroom situation. The subjects were students enrolled in grades three through eight. A control group was formed by matching 705 students from self-contained classrooms with 705 students from laboratory classrooms. The students were matched on the basis of pretest comprehension scores on the Gates-MacGinitie Reading Test. Post-test scores of the Gates-MacGinitie Reading Test were tabulated for each student, and a t-test statistical procedure was computed to determine the significant difference in the two approaches. The results indicated that there was a significant difference in vocabulary in favor of the reading lab group in grades three, four, and six; and that there was a significant difference in comprehension in favor of the reading lab students in grades four, five, six, and eight. (Author/WR)