Final answer:
Matched pairs design involves matching participants based on specific characteristics before assigning them to different experimental conditions.
Step-by-step explanation:
The research design that involves matching participants based on specific characteristics before assigning them to different experimental conditions is Matched pairs design. In matched pairs design, participants are selected based on specific characteristics, such as age or gender, and then assigned to different experimental conditions in such a way that the groups are as similar as possible. This design pairs individuals who are similar in important aspects and then assigns each individual in the pair to different conditions of the experiment. This helps to control for the influence of these specific characteristics on the outcome of the experiment.