A Level Psychology OCR Practice Exam

One disadvantage of quasi-experiments, as discussed in the study, is that participants:

1. Are not allowed to provide consent

2. Are randomly allocated to conditions

3. Might have extraneous variables affecting the results

4. Have guaranteed equal representation

The correct answer is: Might have extraneous variables affecting the results

The correct answer highlights that quasi-experiments often do not control for extraneous variables, which can significantly impact the validity of the results. In quasi-experimental designs, participants are assigned to conditions based on pre-existing characteristics rather than random assignment. This lack of randomization means that there might be external factors—such as differences in participants' backgrounds, experiences, or environmental conditions—that could influence the outcomes. Therefore, the effects observed in a quasi-experiment may be attributed to these extraneous variables rather than the independent variable being studied, making it challenging to establish clear cause-and-effect relationships. In contrast, the other options describe aspects not typically associated with quasi-experimental designs. For example, participants in quasi-experiments can generally provide consent, and since there is no random allocation, guaranteed equal representation is not a feature of quasi-experiments. Random allocation, mentioned in one of the choices, is more aligned with true experimental designs, which aim to eliminate potential extraneous variables.