A male confederate was in a shopping centre for three hours on two different Monday mornings. On the first Monday he wore a suit and on the second he wore gym clothing. Each Monday he asked passers-by if they would be willing to sign up to the same children’s charity. The research used an opportunity sample.
(ii) Explain how the research above could be refined to use a different sampling technique.
[4]
The confederate could use a systematic sample. This would be an improvement from an opportunity sample as it reduces researcher bias and is likely to be more representative of people who donate money to charity.
The confederate could do this either through how he carries out the research e.g. changes to the data collection, or through changes to the setting. For example, he could ask a set number of people on each Monday morning, wearing either a suit or gym clothing to make it a fair test. Alternatively, he could visit every nth house on a street, wearing either gym clothing or a suit, and see if his clothing affects the number of people who sign up to the charity.