Sampling A1 Flashcards
Define Population in terms of sampling
A group of people that are the focus of interest - a smaller sample is drawn from them
Define a sample
A group that is representative of the target population and thus take part in a investigation
Define a Random Sample
Where each member of the target popualtion has an equal opportunity of being picked
How would a random sample be carried out?
Lable all members of target population by numbers or letters
Using a number/letter generator, generate the desired amount of people for the sample
Define a Systematic Sample
When every nth member of the target population is selected
How would a Systematic Sample be carried out?
A sampling frame would be produced and then an interval for which the ppt will be picked is randomly generated
Define a Stratified Sample
When the sample reflects the proportions of people in each strata within the target population
How would a Stratified Sample be carried out?
- Identify each strata
- Work out representative proportions
- Ppts for each strata are randomly selected
Define an Opportunity Sample
Researchers picking ppts that are willing and available by simply asking people in the area
Define a Volunteer Sample
When ppt self-select themselves to be apart of the sample
How would a Volunteer Sample be optained?
By a researcher posting an AD stating they are looking for ppts
What are the strengths of Random Sampling?
- Free from researcher bias
What are the weaknesses of Random Sampling?
- Time-consuming
- Can still create an unrepresentative sample
- Ppts can refuse
What are the strengths of Systematic Sampling?
- No researcher bias
- Fairly Representative
What are the weaknesses of Systematic Sampling?
- Time consuming
