Jia has conducted an experiment on memory. Each participant played a memory game twice, first with a distracting noise and then without the noise.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2019). The mark or mark type is shown in brackets.

1. [1] 1 mark for correctly identifying control condition. No distraction/no distracting noise/no noise (1 mark)
2. [2] 1 mark for identifying why it was important 1 mark for explaining why it was important So they all started from the same baseline ability; (1 mark for identification of why important) avoiding individual differences in ability/amount of (previous) practice (2nd mark for) They might otherwise have remembered it from before the study; (1 mark for identification of why important) so the IV/distraction (or not) would not be the only variable affecting performance (2nd mark for explanation)
3. [2] 1 mark for advantage (can be generic) 1 mark for link It avoids the risk of differences between groups if it had been independent measures; e.g. if the people in one group happened to know a similar game so were better (link) It reduces the likelihood of demand characteristics (as each participant would only experience one condition); as if each participant experienced ‘with noise' and 'without noise' (they might guess and make the effect they believe is supposed to be found happen) (link) It reduces individual differences = 1 mark (no link)
4. [2] 1 mark for identifying problem 1 mark for link A practice effect could occur; e.g. they might learn how the game works/get better at the game (by the second/'no noise' condition) (link) There could be a fatigue effect; e.g. they might get bored/muddled in the 'without noise' condition (so perform worse) (link) A fatigue effect could occur if they are confused by the second condition = 1 mark (no link)
5. [2] 1 mark for identifying a solution, e.g. alternative design/counterbalancing (this mark does not need to be linked to Jia's study) 1 mark for explanation of how it overcomes order effects (this mark must be linked to the study) Independent groups/independent measures/between subjects; (1 mark identification) with different people in each condition they would not practice the (memory) game; (2nd mark explanation – link) as participants do not repeat their performance their memory wouldn't get worse (2nd mark explanation – link) Matched pairs (accept 'matched groups') different people in each condition means they could not get practised/fatigued = 1 mark (identification) so use matched pairs and match people in the noise and no noise groups (2nd mark explanation – link) Counterbalancing = 1 mark (identification) Let half the participants do 'noise' then 'no noise' and half do 'noise' then ‘no noise' (2nd mark explanation – link)