research methods Flashcards
sampling: what is a population
the group of people who are the focus of the researchers interest from which a smaller sample is drawn
what is random sampling
when all members of the population have an equal chance of being selected.
how is a random sample taken
- get a list of all the members of the population
- all names are assigned a number
- write the numbers on pieces of paper and put them in a hat
- randomly choose pieces of paper until you have the desired amount
what is a systematic sample
when every nth number of the population is selected
how is a systematic sample taken
- sampling frame is produced (list of people in the population)
- sampling system nominated
- researcher works through the sampling frame until the sample is complete
what is a stratified sample
a form of sampling where the composition of the sample reflects the proportions of people in certain sub-groups (strata) within the population
how is a stratified sample taken
- identify the different strata
- work out the proportions needed for the sample to be representative
- the participants in each strata are selected using random sampling
what is an opportunity sample/how is it collected
when the researcher selects whoever is around at the time of the study that is willing and available
what is a volunteer sample
participants selecting themselves to be part of the sample
how is a volunteer sample collected
researcher may place an advert in a newspaper or on a common room notice board.
random sampling: evaluation - strengths
free from researcher bias
random sampling: evaluation - limitations
Difficult and time consuming (e.g. a list of the population could be hard to obtain).
You may get a sample that is not representative.
Some participants may refuse to take part (so you end up with more like a volunteer sample)
systematic sampling: evaluation
Avoids researcher bias
Usually fairly representative
stratified sampling: evaluation
Avoids researcher bias
Produces a representative sample
bad:
Identified sample can’t have complete representation of the target population because it can’t reflect all the ways people are different
opportunity sample: evaluation
less time consuming and effort
bad:
Unrepresentative of the target population as it is drawn from a specific area. means findings can’t be generalised.
Researcher bias is possible
volunteer sample: evaluation
less time consuming and effort
bad:
volunteer bias, this means asking for volunteers may attract a certain type of person (curious, helpful etc.). this can affect how far the findings can be generalised
what is qualitative data
data expressed in words.
could be
what is quantitative data
data expressed numerically. could be
what is primary data
original data collected specifically for the investigation.
could be by questionnaire, interview, observation etc.
what is secondary data
data that has already been collected by someone else.
could be journal articles, books, websites etc.
qualitative data: evaluation - strengths
Richer in detail.
This means it usually has greater external validity than quantitative data because it gives a more meaningful insight.
qualitative data: evaluation - limitations
Difficult to analyse as it usually can’t be summarised statistically so its harder to identify patterns.
This means conclusions often rely on subjective interpretations of the researchers so they may be subject to bias
quantitative data: evaluation - strengths
easy to analyse so comparisons between groups can be easily drawn
More objective so less open to bias.
quantitative data: evaluation - limitations
has a narrower scope and meaning than qualitative data so it may fail to represent ‘real life’ / the participants full experience
