Sampling techniques and pilot studies Flashcards
What is a target population?
Everyone your research is meant to represent
What is a sample?
A group of participants used in the research
What is a sampling frame?
A list of people in the population who can be sampled
What is Random sampling?
Everyone in the target population has an equal chance of being chosen for the sample
Explain how you would use random sampling to select a sample of 100 students out of 2000
1-Allocate each person a number
2-Use a random number generator to choose the 100 people (sample)
What are two strengths of random sampling?
-Everyone has an equal chance of being chosen
-It avoids researcher bias
What are the 2 limitations of Random sampling?
1-It requires a sampling frame
(impractical)
2- May be an unrepresentative sample to the target
(results cant be generalized to the target population)
What is systematic sampling?
Selecting evert 3rd/4th etc member of the target population used
Explain how you would use systematic sampling to select a sample of 100 students out of 2000
You would select every 20th person which would give you the sample of 2000
What is the 1strength of systematic sampling?
Avoids researcher bias
What are the 2 limitations of systematic sampling?
-Requires sampling frame
-May be unrepresentative sample to the target
What is stratified sampling
Dividing the subject into sub-groups of similar characteristics, then using random sampling to choose the sample from each subgroup
Explain how you would use stratified sampling to select a sample of 100 students out of 2000
Divide the 2000 students into subgroups of similar characteristics, then allocate each person a number, and use a random number generator to choose the sample of 100 people from the subgroups.
What are 2 strengths of stratified sampling?
Representative to the whole target population
Avoids researcher bias
What are 2 limitations of stratified sampling?
Requires a sampling frame
Time-consuming
What is opportunity sampling?
Using participants who are available to the researcher
Explain how a psychology teacher would use opportunity sampling to select a sample of 100 students out of 2000
The teacher could use his psychology class students as a sample as they’re readily available
What is a strength of opportunity sampling?
It’s easy and convenient
What are 2 imitations of opportunity sampling?
-May be a biased sample as ppt may share similar characteristics
(eg all taught the same way)
-May be unrepresentative sample to the target
What is volunteer sampling?
Where participants volunteer to take part in a study (usually in response to an advert)
Explain how you would use Volunteering to select a sample of 100 students out of 2000
The researcher could put out an advert of the experiment he’s doing and volunteers could come forward and volunteer to take part
What is a strength of Volunteering?
Participants are keen to take part
What are 2 limitations of volunteering?
Volunteer bias
(certain types of people volunteer)
Researcher bias
(researcher may have advertised to a particular type of people)
Which sampling techniques are more likely to produce a biased sample?
Volunteer and opportunity sampling
Which sampling technique is most likely to be representative of the target population?
Stratified sampling
What is a pilot study?
A small-scale run of the actual investigation to ensure it runs smoothly and identify any changes that need to be made
What 4 things may be checked in a pilot study?
1- If ppt understood the task
2-Have the ppt been given enough time
3- Are the materials used clear
4-Are the questions clear in a questionnaire?
