Dement and Kleitman studied participants who were asleep. Explain one limitation in research with participants who are asleep that does not apply to participants who are awake. You must refer to the study by Dement and Kleitman in your answer.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2020). The mark or mark type is shown in brackets.

1. 1 mark for limitation
2. 1 mark for link
3. You cannot talk to them = 1 limitation
4. So Dement and Kleitman had to wake them up, then they were not asleep anymore = 1 link
5. Participants forget their dreams while they are sleeping = 1 limitation
6. So Dement and Kleitman could probably only find out about recent dreams from the participant = 1 link
7. Sleeping participants are still sleepy when they wake up = 1 limitation
8. So Dement and Kleitman would only have found out partial data about the dreams = 1 link
9. Participants who are awake can estimate time durations accurately but sleeping participants may not be able to = 1 limitation
10. So Dement and Kleitman had to limit estimation to a guess of 5 or 15 minutes when they were asleep = 1 link