A science institute wants to evaluate the effectiveness of a new instructional approach for teaching high-school earth science. Teachers in a school district are being trained in the approach through summer workshops. A central feature of the approach is that students gather and analyze field data. In addition, students are assigned to cooperative project teams in which each team is responsible for collecting a different data set. Advocates maintain that the approach leads to increased student learning than traditional didactic methods of teaching earth science.

The workshop developers have designed the workshop to be hands-on. Its main agenda is to have teachers participate in data gathering and analysis. In turn, teachers will employ the same data gathering and analysis activities with their own students. The workshop culminates with teachers using the new instructional method to design a curriculum unit. The teachers are expected to implement this unit in the following year.

The evaluation questions are as follows.

1. Has the workshop been implemented as planned?
2. Are the teachers who have participated in the workshop producing curriculum units that maintain fidelity to the approach?
3. Are teachers maintaining fidelity to the instructional approach as they implement their new units?
4. Is there evidence of a relationship between the teachers' workshop participation and their students' earth science achievement?

To answer the fourth evaluation question, you decide to set up a quasi-experimental design in which you gather the same student learning outcome data from a comparison group of earth science teachers. The comparison group is matched demographically with the school district. Teachers in the comparison group are using a traditional didactic instructional approach (see the Methodological Approach and Sampling Module for more on different types of evaluation designs).