sampling: evaluation Flashcards
what is a strength of random sampling
random sampling is free form researcher bias
This is because the researcher has no influence who is selected and this prevents them form choosing people who they think may support their hypothesis
what are some limitations of random sampling
- difficult and time - consuming
- a complete list of the target population may be extremely difficult to obtain
- the sample may end up being unrepresentative. Although, the laws of probability suggests that random sampling is likely to produce a more representative sample than e.g. opportunity sampling
- selected participants may refuse to take part ( which means you end up with something more like a volunteer sample)
what are some strengths of systematic sampling
- it avoids researcher bias as once the system for selection has been established, the researcher has no influence over who is chosen ( even more the case if the system is randomly selected)
- fairly representative
what is a limitation of systematic sampling
it is unlikely but possible to get an all - male sample through systematic sampling
what are some strengths of stratified sampling
- avoids researcher bias as once the target population has been sub - divided into strata, the participants that make up the numbers are randomly selected and beyond the influence of the researcher
- representative sample because it is designed to accurately reflect the composition of the population. Therefore, generalisation of the findings becomes possible
what is a limitation of stratified sampling
stratified sampling is not perfect. This is because the identified strata can’t reflect all the ways that people are different, so complete representation of the target population is not possible
what is a strength of opportunity sampling
it is convenient as it saves a researcher a good deal of time and effort and is much less costly in terms of time and money than, say random sampling
what is a limitations of opportunity sampling
opporttunity sampling suffrs form two forms of bias :
1) the sample is unrepresentative of the target population as it is drawn from very specific area so findings can’t be genneralised to the whole target population
2) the researcher has complete control over the selection of participants and may avoid people they do not like the look of ( researcher bias)
what are some strengths of volunteer sampling
1) it is easy
2) requires minimum input fro the researcher ( they come to you) , therefore, it is less time consuming
what is a limitation of volunteer sampling
volunteer bias is a problem
Asking for volunteer may attract a certain profile of person e.g. someone who is helpful, curious. This might affect how far findings can be generalised