Final answer:
Two disadvantages of using Within-Subject Design are increased risk of carryover effects and the requirement of a larger sample size. Additionally, Within-Subject Design has limited generalizability and higher costs of implementation.
Step-by-step explanation:
One disadvantage of using Within-Subject Design is the increased risk of carryover effects. This refers to the possibility that the effects of one condition that a participant experiences may carry over and affect their responses in subsequent conditions.
Another disadvantage is that Within-Subject Design requires a larger sample size compared to other research designs. This is because each participant serves as their own control and is exposed to multiple conditions, which necessitates a larger sample to ensure adequate statistical power.
A third disadvantage is the limited generalizability of findings obtained from Within-Subject Design. Since participants are typically selected based on specific criteria, such as age or ability, the findings may not be applicable to the broader population.
Lastly, Within-Subject Design may involve higher costs of implementation. It can be more time-consuming and resource-intensive to collect data from the same participant across multiple conditions.