Final answer:
Ken is using a nonequivalent control group design, where two groups are compared after one group receives an intervention and the other does not. It helps suggest causal relationships but has limitations due to potential group differences.
Step-by-step explanation:
The design Ken decides to implement, where an intervention is introduced to one daycare but not another, and then followed up with a reading readiness test for both groups, is known as a nonequivalent control group design. This type of experimental design involves choosing two groups that are as similar as possible, but not identical, because the participants were not randomly assigned. One group, the experimental group, receives the intervention, while the other group does not receive the intervention and serves as the control group.
The strength of this approach lies in its ability to suggest possible causal relationships between the intervention and the outcomes measured by the test. However, a potential weakness is that the control group and the test group may have systemic differences that could affect the results, making it more difficult to determine whether the intervention itself produced the changes observed.