Psychology: Sampling Techniques and Pilot studies

Question 1

What is the difference between a target population and a sample?

Answer 1

• A sample is the name given to the group of participants used in research.
• A sample is to identify the target population.
• A target population is everybody that your research is meant to represent.

Question 2

What is a sampling frame?

Answer 2

A list of all the people forming a population from which a sample is taken.

Question 3

What is Random Sampling?

Answer 3

Allocate each person of the target population a number generator to choose 100 numbers. The names against these numbers are the sample.

Question 4

What is Stratified Sampling?

Answer 4

Important Characteristics of the target population are listed e.g. sex, age, class ect and the sample is chosen that will represent each of these characteristics.

Question 5

What is Opportunity Sampling?

Answer 5

This involves using participants who are easily available to the researcher. For example most psychology students as the sample - as they are readily available.

Question 6

What is Volunteer Sampling?

Answer 6

In this case participants volunteer to take part - usually in response to an advertisement.

Question 7

What is Systematic Sampling?

Answer 7

This is when every 3rd/4th/5th (whatever) member of the target population is used. To do this properly a sampling frame (a list of all in the target population) is needed. The ‘system’ used to choose the sample (e.g. every 3rd person) can then be applied.

Question 8

A Strength and limitation of Random Sampling?

Answer 8

Strength: Everybody had an equal chance of being drawn (no researcher bias)
Limitation: Requires access to all members of the target population (sampling frame)

Question 9

A Strength and limitation of Stratified Sampling?

Answer 9

Strength: Everybody had an equal chance of being drawn (no researcher bias)
Limitation: Requires access to all members of the target population (sampling frame)

Question 10

A Strength and limitation of Opportunity Sampling?

Answer 10

Strength: Easy to do and not time consuming
Limitation: Likely to produce a biased sample with similar characteristics.

Question 11

A Strength and limitation of Volunteer Sampling?

Answer 11

Strength: Easy to do and not time consuming
Limitation: Likely to produce a biased sample with similar characteristics.

Question 12

A Strength and limitation of Systematic Sampling?

Answer 12

Strength: Everybody had an equal chance of being drawn (no researcher bias)
Limitation: Requires access to all members of the target population (sampling frame)

Question 13

What is a Pilot Study?

Answer 13

A pilot study is a small scale run of the actual investigation to check that the process runs smoothly and see if any changes need to be made. It usually involves fewer participants that the main study.

Question 14

What checks can be done during a Pilot Study?

Answer 14

~ Have the participants fully understood the task - are the instructions clear?
~ Have they been given enough time for the task?
~ In an observation are the behavioural categories clear - do any need to be changed/added?
~ Are the materials used clear and appropriate - this will depend on the study e.g. ina memory study - word list, photos to be remembered ect.