Experiments: Sampling Flashcards
What is the participant
The individual taking part in the research
What is the sample
- The group of participants taking part in the research
- it should be representative of the target population
What is the target population
The group a researcher is interested in researching
- e.g. schizophrenics/students/etc
What is the sampling frame
The list of ‘items’ which a sample is drawn from (i.e. a more manageable number)
What does it mean if a sample is representative
The sample illustrates/reflects the target population
What does it mean if a sample is generalisable
Applying the findings to the population
What does it mean if a sample is Gender bias
The sample is focused or centred on one gender and therefore it is distorted
What does it mean if a sample is Androcentric
- The sample is focused or centred on men
- this is a problem because you can’t generalise the findings to women if only men are represented
What does it mean if a sample is ethnocentric
- Evaluating other cultures according to preconceptions originating in the standards and customs of one’s own culture that has been sampled
- One group is seen as superior to another
Why is having a large sample good
- less likely to be biased (participant variables will be minimised )
- more likely to be representative of the target population so findings are easily generalised to the target population
Why might having a large sample be bad
- more time consuming for the researchers to find = costly
- more time consuming for analysing the data = costly
Describe the sampling Method: Opportunity sampling
- selects a group of participants based on the section of the population given at a given time
- e.g. a researcher may use people at local supermarket at the time
Describe the sampling Method: Random sampling
- every member of target population has an equal chance of being selected
- to gather random sample = access to everyone in target population, then use the lottery method or random number generator
Describe the sampling Method: snowball method
- relies on referrals from initial participants to generate additional participants
- e.g. participants already obtained are asked to ask people they know if they would also like to participate
Describe the sampling Method: self selected
- produced by asking for volunteers to take part in the research
- participants select themselves (through advertisements)
Describe the sampling Method:systematic sampling
- predetermined system is used to select participants form the target population
- e.g. every nth person
- number of participants selected depends on how big the sample is
Describe the sampling Method: stratified and quota sampling
- very similar to each other
- select participants based on frequency in the population
- therefore ratio of groups in sample = same as in target population
- the sub groups (strata) within population are identified and selected according to incidence
- for stratified: individuals selected using random technique
- for quota: opportunity technique is used
What is a strength and a weakness to: Opportunity sampling
Strength:
- quick and easy to select the sample as just taking advantage of the people available
Weakness:
- may be biased as it consists of people in a certain area at a certain time, who are likely to be similar in some way. Therefore its unlikely to be a representative of the target population
What is a strength and a weakness to: Random sampling
Strength:
- everyone in target population has an equal chance of being selected
- therefore sample should be representative of the target population
Weakness:
- More complex + time consuming, because you need access to a list of whole population = difficult if target population is large
- once selected, participants might not actually want to take part
What is a strength and a weakness to: snowball sampling
Strength
- allows researcher to locate groups of people who are difficult to access such as drug addicts or people with specific disabilities
Weakness
- unlikely to be very representative as all the participants will be similar people because they are all friends of friends
What is a strength and a weakness to: Self selected sampling
Strength
- running ads in areas where you can get big publication = gain a large sample with broad range of people
- consent in’t a problem = people who volunteer are giving their consent
Weakness
- sample is likely to be biased, people who volunteer = similar: helpful and inquisitive natured
What is a strength and a weakness to: systematic sampling
Strength
- obtains an unbiased sample as they are selected using a predetermined, objective, consistent system
Weakness
- not truly unbiased unless you chose a number using a random method and stick with this process
- need access to list of all target population
- those selected might not be willing to take part
What is a strength and a weakness to: Stratified/quota sampling
Strength
- its a representative sample compared to other techniques, because there’s equal representations of all the sub groups in the target population
Weakness
- difficult + time consuming = sub groups need to be identified and proportions calculated before the sample is selected
- in quota: each quota may be biased when selecting by opportunity sampling
