Sampling Techniques

Question 1

Explain what is meant by “population”.

Answer 1

Population is the group of people the researcher is interested in.

Question 2

Explain what is meant by ‘sample”.

Answer 2

Sample is the smaller group of the population that represent the whole of the population

Question 3

What are the five types of sampling ?

Answer 3

Random sampling, Volunteer sampling, Opportunity sample, Stratified sampling, Systematic sampling

Question 4

Explain random sampling and give advantages and disadvantages.

Answer 4

All members have equal chance of selection. The sample would be generated using a hat or random generator.

Advantages :

• Unbiased
• High internal validity

Disadvantages :

• Time consuming
• Could end up with unrepresentative sample

Question 5

Explain volunteer sampling and give advantages and disadvantages.

Answer 5

People volunteer themselves to take place.

Advantages :

• Easy to do
• Not time consuming

Disadvantages :
- Volunteer bias ( will only attract interested people )

Question 6

Explain Systematic sampling and give advantages and disadvantages.

Answer 6

Every n’th member of a target population is selected EG every 4th person.

Advantages :

• Not costly
• Not time consuming

Disadvantages :

• Researcher bias ( researcher decides where to get sample EG: people from the same street etc. )
• Could be unrepresentative of full population

Question 7

Explain stratified sampling and give advantages and disadvantages.

Answer 7

Sample represents subgroups within target population. Proportions need to be proportionate to population EG if there’s 10% men in population of 200 and you need a sample containing 100, 10% of the 100 should be men.

Advantages :
- Generalisation

Disadvantages :
- Complete representation of population is not possible

Question 8

What does “bias” mean.

Answer 8

Bias means distorted in some way based on the persons opinion and feelings toward something.

Question 9

What does “generalisation” mean.

Answer 9

Generalisation means sample will be representative of population so results can be generalised to population.

Question 10

Explain Opportunity sampling and give advantages and disadvantages.

Answer 10

Opportunity sampling is when you use the ppts available to you.

Advantages:

• Easy
• not time consuming
• cheap

Disadvantages:
- Very unrepresentative