samples and sampling
what is sampling bias
when the sample or samplingvtechnique is biased towards
1. one gender.
2. a certain target population.
3. age-range.
4. culture (ethnocentrism).
5. soical class.
6. income.
7. race.
8. sample size.
what are the advantages of biased sample
1. easier for the researchers to recruit participants.
2. this can save time for the researchers which may mean more participants can be recruited.
3. researchers can focus on.
what are the disadvantages of biased sample
1. the sample is unrepresentative and therefore cannot be generalised to the wider population.
2. the rsearch may be valued less in the real world if the sample is limited.
3. low population validity which means the samlpe isn't measuring enough of the population to be measuring what it intends to.
what are the four sampling techniques
1. random.
2. snowball.
3. oppitiy.
4. self-selected.
what is random sampling
when the target population has an equal change of being chosen for example names out of a hat.
what are the advantages of random sampling
1. unbiased.
what are the disadvantages of random sampling
1. time consuming to make a list of all potential participants epecially if you want a large sample.
2. some participants may be less willing/not want to particpate - then need to find more.
what is snowball sampling
asking participants to nominate anohter person for example give a questionnaire to a friend.
what are the advantages of snowball sampling
1. can find people with rare charactertics/traties.
what are the disadvantages of snowball sampling
1. can be time consuming.
2. sample might be biased - all similar people.
what is opportunity sampling
selecting people that are readily available at the time for example going up to people in a supoermarket
what are the advantages of opportunity sampling
1. quick.
2. cheap.
3. convenient.
what are the disadvantages of opportunity sampling
1. usually biased - may choose people that look 'helpful' or friendly.
2. unrepresentative (only people who happen to be in that place at that time).
what is self-selecting sampling
when participants select themsevles to participate. usually through an advert. also known as self-selecting sampling.
what are the advantages of self-selecting sampling
1. participants are willing - may be less likely to drop out.
what are the disadvantages of self-selecting sampling
1. time cosuming waiting for participants.
2. may have an unreprsentative sample.
what is ethoncentrism
1. a bias when we see things from the point of view of ourselves and out social group - a cultural bias.
2. evaluating other groups of people using the standards and customs of one's own culture.