Final answer:
To change the study to a within-groups design, the same participants would be exposed to all experimental conditions, acting as their own control. Statistical analysis like a paired t-test or repeated measures ANOVA would be used to compare participant performance across different phases.
Step-by-step explanation:
To transform the study into a within-groups design, a researcher would need to ensure that the same participants are exposed to every condition of the experiment, rather than having separate groups for each condition as is done in a between-groups design. In a within-groups design, also known as a repeated-measures design, each participant acts as their own control, which helps to control for individual differences among subjects.
For example, if the original study had an experimental group receiving tutoring and a control group not receiving tutoring, in a within-groups design, all participants would receive tutoring during one phase of the experiment and no tutoring in another phase. The order of these phases could be randomized to control for any order effects. Data would then be collected on the performance of the participants in both phases.
Statistical analysis such as a paired t-test or repeated measures ANOVA could be used to compare the participants' performance across the different phases of the experiment. These analyses take into account the fact that the same participants took part in both conditions, allowing the researcher to assess the effect of the experimental manipulation more directly.