School officials are concerned about dropping scores across the district in 5th grade mathematics standardized tests. Specifically, students are struggling with addition and subtraction of fractions. The district mathematics curriculum coordinator has identified three new programs for revamping how 5th graders are taught these skills. The curriculum director has been instructed to set up a research study to be conducted over the first three months of the next school year to decide which program, if any, should be adopted. How would you set up the required research study? Be sure to include in your discussion the following: (please answer each question separately)
1. the number of groups you would need
2. how many students in each group
3. the selection of teachers to participate
4. how you would collect and analyze the data.
5. identify all variables by type and potential covariates/confounding variables that you might need to control.

NOTE: Please do not introduce any new variables (e.g., student gender) when you describe your study!