Final answer:
The effectiveness of debriefing can be increased by conducting it immediately after the study and using written materials. Making debriefing longer may not be effective, and omitting it is not recommended. option (c)
Step-by-step explanation:
According to a study by McFarland, Cheam, and Buehler (2007), the effectiveness of debriefing can be increased by conducting debriefing immediately after the study. This allows participants to recall their experience and provide accurate feedback. Additionally, using written debriefing materials can aid in providing clear instructions and minimizing confusion. Making debriefing longer may not necessarily increase effectiveness, as participants may become fatigued or lose interest. Omitting debriefing altogether is not recommended, as it violates ethical guidelines and can lead to participant dissatisfaction.