AQA A-level Psychology research methods Set 5

what is random allocation

assigning pts evenly to spread out characteristics using random techniques

what’s the problem with matched pairs

time consuming

why is matched pairs time consuming

pts only take place in 1 of 2 conditions so it is time consuming and expensive to get more pts who are matched

what is a a sample

The smaller group of participants actually selected from the target population to take part in the study.

what does representative mean

pts who are typical of the population in question, if it is representative we can generalise the behaviour

what is random allocation

everyone in the target population has an equal chance at being selected

how is random allocation carried out

1.obtain list of names from target population

2.put names into hat and select names

3.give a number to everyone in target population 4.use computer to select random numbers

what ae the strengths of random allocation

likely to be unbiased since all members of population have equal chance at selection

what is a weakness of random allocation

fails to produce a truly representative sample as its very hard for an experimenter to obtain a random sample (cannot identify ALL members in population)

what is opportunity sampling

involves selecting pts on their availability

how do you carry out opportunity sampling

researcher approaches people and asks them to take part, sample is those who agree

what are the strengths of opportunity sampling

easiest method to use, choose first person who agrees, takes less time

what is a weakness of opportunity sampling

a biased sample drawn from a small part the target population, small sample of those who were there

what is volunteer sampling

participants self-select

how do you carry out volunteer sampling

researcher advertises the study and need for pts e.g. newspaper and people respond

what are the strengths of volunteer sampling

allows access to a variety of different individuals who read e.g. the news paper so more representative than opportunity

what are the weakness’s of volunteer sampling

sample is biased as people likely to respond are highly motivated/ more likely to look for demand characteristics (they’re helpful individuals)

what is stratified sampling

population is split into groups (strata) based on key characteristics People are then chosen randomly from each group, in the same proportions in the population.

how is stratified sampling carried out

1.Split the population into groups (strata) based on key features, like gender or age.

2.Work out what proportion of the population each group makes up.

3.Randomly pick people from each group in the same proportions.