To determine the best plan for testing the intensive remediation programs, we need to analyze the strengths and weaknesses of each option. Let's break it down:
Plan a:
- Random assignment of students to three groups (A, B, and C) provides equal opportunity for each student to be in any group, minimizing bias.
- The intervention is implemented for a period of 6 weeks, which allows for an adequate duration to assess the effectiveness of the program.
- The counterbalancing of Group B and C switching programs helps control for any potential confounding variables or individual differences.
- Diagnostic exams and mathematics concept tests are conducted by the school psychologist at the beginning and end of the intervention phase, providing pre- and post-intervention data for comparison.
Plan b:
- This plan is similar to Plan a but extends the intervention phase to 12 weeks, providing more time for potential effects to be observed.
- The additional duration may lead to more conclusive results for the effectiveness of the programs.
Plan c:
- Random assignment of students to two groups (A and B) still provides equal opportunity for each student to be in any group.
- The intervention is implemented for a period of 12 weeks, allowing for a sufficient intervention duration.
- However, the absence of a control group (Group A) not receiving the new services makes it challenging to isolate the effects of the intervention.
Considering all these factors, the best choice would be Plan a (#1) since it includes random assignment, a control group, a counterbalancing design, and pre- and post-intervention assessments. Plan b (#2) could also be a viable option due to the extended intervention period, but it lacks the counterbalancing aspect of Plan a. Plan c (#3) is the least favorable choice since it lacks a control group, making it difficult to evaluate the true impact of the intervention.
Disclaimer: The choice of the best plan ultimately depends on various factors, including available resources, time constraints, and any other specific considerations relevant to the district's situation.