Ed and Jim are planning a field experiment about learning. They want to know whether young children learn to use mobile (cell) phones from older brothers or sisters. They each offer their phone to a younger brother or sister and also to a cousin who has no older brothers or sisters. They time how long it takes each child to find a game to play with on the phone.

Mark scheme

Marking points from the official mark scheme (May/June 2018). The mark or mark type is shown in brackets.

1. [2] For fewer demand characteristics, as children would be less self-conscious about being watched in a natural setting.
2. [2] For higher ecological validity, as children play at home and might not act naturally in a lab setting.
3. [2] Independent measures / groups / between subjects design is used because a child either did or did not have older siblings, meaning different children are in each condition.
4. [3] **Control:** Age of child. **Justification:** Older children would likely be better on phones, or younger ones might be more inclined to play, which could affect the results. **Implementation:** Have both groups of children (siblings and cousins) be approximately the same age, e.g., both aged 6 years.
5. [3] **Control:** Use the same phones / same apps for all children (for Ed and Jim / for siblings and cousins). **Justification:** Otherwise, it could be a confounding variable due to individual differences in familiarity or difficulty. **Implementation:** Ensure all children use identical phone models with the exact same game pre-installed.
6. [3] **Control:** Standardised instructions. **Justification:** Different instructions could affect how quickly children find the game. **Implementation:** All children are given the exact same instructions, or no instructions, on how to find the game.