Sampling Techniques Flashcards
1
Q
Population
A
Group of people who are the focus of the researchers interest
2
Q
Sample
A
Group of people who take part in an investigation
3
Q
Sampling techniques
A
Method used to select people from a population
4
Q
Bias
A
When certain groups are over/under represented within the sample selected
5
Q
What are the 5 sampling techniques?
A
- Random
- Stratified
- Opportunity
- Volunteer
- Systematic
6
Q
Random sampling
A
- all members of the target population have an equal chance of being selected
- complete list of all members of the target population is obtained and they are all assigned a number of
- sample is generated through the use of a lottery method (computer number generator, numbers from a hat)
7
Q
Strengths of random sampling
A
- no researcher bias
8
Q
Weaknesses of random sampling
A
- time consuming (list of all members in a population is difficult to obtain)
- may have an unrepresentative sample
- volunteer bias (selected p’s may refuse to take part)
9
Q
Systematic sampling
A
- every nth member of the target population is selected
- sampling frame is produced (list of people in the population organised into a certain order (alphabetical order))
- sampling system determined randomly to reduce bias
10
Q
Systematic sampling strengths
A
- avoids researcher bias BUT not truly unbiased
- fairly representative
11
Q
Opportunity sampling
A
- researchers select anyone who happens to be willing and available, asks whoever is around at the time of the study
12
Q
Opportunity sampling strengths
A
- saves time, money, effort
13
Q
Opportunity sampling weaknesses
A
- unrepresentative so findings cant be generalised
- researcher bias as researcher has complete control over the selection of p’s
14
Q
Stratified sampling
A
- composition of the sample reflects the proportions of people in certain subgroups/strata within the population
- researcher identifies the different strata and the proportions needed for the sample to be representative is calculated
- p’s that make up each stratum are selected using random sampling
15
Q
Stratified sampling strengths
A
- no researcher bias
- representative sample that can be generalised
16
Q
Stratified sampling weaknesses
A
- complete representation of the target population isn’t possible as the identified strata can’t reflect all the differences between people
17
Q
Volunteer sampling
A
- p’s selecting themselves to be part of the sample (self-selection)
- could be through an advert or responding when a researcher asks by raising their hand
18
Q
Volunteer sampling strengths
A
- easy and less time consuming
19
Q
Volunteer sampling weaknesses
A
- volunteer bias, may attract a certain profile of person which affects generalisability
