Final answer:
The correct statement about a matched-pair design is that subjects within pairs are randomly assigned to either the control or treatment group to control for confounding variables and provide more reliable results. This random assignment is crucial to prevent lurking variables from affecting the outcome, ensuring observed differences are due to the treatment.
option d is the correct
Step-by-step explanation:
The correct statement for a matched-pair design is option A, which says: the matched pair subjects are randomly assigned, one member to the control and the other to the treatment. In matched-pair design, subjects are paired based on a certain characteristic they share and then within each pair, they are randomly assigned to different groups to ensure that each treatment group has similar characteristics. This experimental design aims to control for known and unknown variables that could confound the results, thereby reducing variability and improving the reliability of the results.
Matched-pair designs typically involve random assignment to control or treat groups, and they allow for pairwise comparison. It works on the principle that there is a pairing of units such as two measurements taken from the same individual, before and after treatment, or subjects matched on a relevant characteristic, with one subject in each pair receiving each treatment.
Random assignment is crucial in this design to eliminate the presence of lurking variables, meaning that elements outside of the experimental control do not affect the outcome. The primary purpose is to ensure that aside from the imposed treatment, there is no significant difference between the groups, and any observed effects can be attributed to the treatment itself.