Sampling Techniques Flashcards
Random Sampling
Every member of the target group has an equal change of being selected for the sample
Random Sampling (Strengths)
No Researcher Bias since each member has the same probability of being selected making it a representative sample
Random Sampling (Weakness)
Time Consuming, the target group may be to large to assign numbers too
Systematic Sampling
Every N(th) member is selected from the target group
Systematic Sampling (Strengths)
Assuming the list order is randomised, this method offers an unbiased chance of gaining a representative sample
Systematic Sampling (Weakness)
List assembled in any other way, it attracts a bias
Stratified Sampling
‘Stratifies’ the target group into sections each showing a key characteristic which should be present in the final sample.
Stratified Sampling (Strengths)
Avoids the problem of misrepresentation sometimes caused by random sampling
Stratified Sampling (Weakness)
Takes more time and resources to plan
Care must be taken to ensure each key characteristic present in the population is selected across strata, otherwise this will design a biased sample.
Opportunity Sampling
Participants who are both accessible and willing to take part are targeted
Opportunity Sampling (Strengths)
Method is easy and inexpensive to carry out
Opportunity Sampling (Weakness)
May not be representative as it could be subject to bias
Volunteer Sampling
Sample consists of people who have volunteered to be in the study due to advertisements
Volunteer Sampling (Strengths)
Often achieves a large sample size through reaching a wide audience e.g online advertisements
Volunteer Sampling (Weakness)
Those who respond to the call for volunteers may all display similar characteristics, increasing the chances of an unrepresentative sample
