From the study by Fagen et al. (elephant learning):

Mark scheme

Marking points from the official mark scheme (Feb/Mar 2024). The mark or mark type is shown in brackets.

1. [2] This is the addition of something nice/reward after a behaviour to increase the probability of repeating a behaviour (2 marks).
2. [1] It is giving a reward to someone/the elephants were given (chopped) bananas (1 mark: positive part of the definition).
3. [1] It is trying to help someone repeat a behaviour (1 mark: reinforcement part of the definition).
4. [3] Elephant 2 took fewer sessions to pass the trunk compared to Elephant 4. It took elephant 2, 25 sessions.
5. [3] The juvenile elephants passed within 25–35 sessions/all within 35 sessions whereas as the older elephant never passed.
6. [2] Elephant 2 took fewer sessions to pass the trunk compared to Elephant 4.
7. [2] The juvenile elephants passed within 25–35 sessions.
8. [1] Elephant 2 required the least number of sessions (to pass).