Sampling Techniques Flashcards
Target population
Who you are interested in
Sample
From the target population who you test/observe/give questionnaire to
Sampling technique
How you get the sample
Random sample
Everyone from target population has an equal chance of being selected
Systematic sample
Every nth person chosen from a list
Stratified sample
The proportions of people in a population sub groups (strata) are reflected in the sample. Eg- 80% of people in Leeds support Leeds united then 80% of sample should support Leeds united eg 8/10
Opportunity sample
People available at the time of sampling will be included
Volunteer sample
Participants self select
Pros and cons for RANDOM sampling
Pro- equal chance so unbiased
Con- often not possible
Pros and cons for SYSTEMATIC sampling
Pro- random and so unbiased avoids researcher bias
Con-could be unlucky and sample all of one category eg- males
Pros and cons of STRATIFIED sampling
Pro- representative of target population, and once stratified sample is chosen randomly (no bias)
Pros and cons of OPPORTUNITY sampling
Pro- quick and easy, practical
Con- sample influenced by where people are asked (small demographic)
Pros and cons of VOLUNTEER sample
Pro- varied sample
Con- volunteer bias (attracts a certain type of person)
