Flashcards in RESEARCH METHODS - sampling Deck (15):
what is random sampling
This method gives every member of the target group an equal chance of being selected for the sample (e.g. by assigning a number to each member, and then selecting from the pool at using a random number generator).
random sampling weakness
It can be impractical (or not possible) to use a completely random technique, e.g. the target group may be too large to assign numbers to.
random sampling strength
sample should represent the target population and eliminate sampling bias
Here the sampler divides or 'stratifies' the target group into sections, each showing a key characteristic which should be present in the final sample.
Then each of those sections is sampled individually.
The sample thus created should contain members from each key characteristic in a proportion representative of the target population.
stratified sampling strength
highly representative of the target population and therefore we can generalize from the results obtained.
stratified sampling weakness
Uses people from target population available at the time and willing to take part. It is based on convenience.
opportunity sampling weakness
The consequent sample may not be representative as it could be subject to bias
opportunity sampling strength
easy and inexpensive to carry out
systematic sampling strength
Assuming the list order has been randomised, this method offers an unbiased chance of gaining a representative sample.
Chooses subjects in a systematic (i.e. orderly / logical) way from the target population, like every nth participant on a list of names.
systematic sampling weakness
If the list has been assembled in any other way, bias may be present. For example if every fourth person in the list was male, you would have only males in your sample.
Here the sample consists of people who have volunteered to be in the study.
volunteer sampling strength
This often achieves a large sample size through reaching a wide audience, for example with online advertisements.