The instructor and the interviewer were experts on PBL and clearly had full knowledge of the instructional method each participant received. This could be construed as a limitation of the study and would be important to consider in future studies.
The classes were originally comparable in terms of students labeled as “high need” (i.e., those reading below their grade level and those who spoke English as a second language).
Both classes were taught using an inclusion model, with 19 students being present in the comparison group and 21 students being present in the PBL experimental group.