sampling techniques Flashcards
what is a target population?
The group that the researchers draws the sample from and wants to be able to generalise the findings to.
what is a random sample?
the first participants to be randomly picked out of the target population
what is an opportunity sample?
a sample of using the first people that you can find
what is a stratified sample?
a sample created by dividing the target group into sections, each showing a key characteristic. Then each of those sections is sampled individually and combined to make a whole sample.
what is a systematic sample?
A sample using a systematic method is chosen for selecting from a target group, e.g. every fourth person in a list could be used in the sample.
what is a volunteer sample?
a sample made from people who volunteered to be in the study that fit the characteristics needed
what are the strengths of a random sample?
each member has the same probability of being selected = representative sample.
what are the weaknesses of a random sample?
Small minority groups within your target group may distort results
It can be impractical (or not possible) to use a completely random technique
what are the strengths of an opportunity sample?
This method is easy and inexpensive to carry out
what are the weaknesses of an opportunity sample?
the sample could be bias as it is made up of the first people you come across so therefore could be made up of one type of person
what are the strengths of a stratified sample?
avoids bias and misrepresentations
what are the weaknesses of a stratified sample?
time consuming
it must be carefully planned to ensure each key characteristic is included otherwise it is bias
what are the strengths of a systematic sample?
offers a chance at a unbiased sample as long as the order has been randomised
what are the weaknesses a systematic of sample?
if the order wasnt randomised and every nth person was a ceratin key characteristic then it would be bias
what are the strengths of a volunteer sample?
