Sampling

Question 1

What is a random sample?

Answer 1

All members of the target population have an equal chance of being chosen.

Question 2

Random sample eval

Answer 2

+Unbiased
- impractical

Question 3

What is stratified sampling?

Answer 3

• Select strata (group) + proportion in wider target pop
• Random sampling is used to select the number of ppt required within each stratum
• So the sample is reflective / same proportion of the wider population

Question 4

Stratified sampling evaluation

Answer 4

+Avoids bias
+Representative → so more generalisable
- Takes time
- expensive

Question 5

What is systematic sampling?

Answer 5

Every nth member of the population is selected.

Question 6

Systematic sampling evaluation

Answer 6

Strengths
Quick and easy
Not costly
Practical strength

Limitations
could get an all male / unrepresentative sample
Could be biassed as not random

Question 7

What is opportunity sampling?

Answer 7

Researcher takes the chance of whoever is around at the time

Question 8

Opportunity sampling evaluation

Answer 8

+ quick and convenient
- not representative

Question 9

What is volunteer sampling?

Answer 9

Participants chose themselves through advertisements

Question 10

Volunteer sampling evaluation

Answer 10

+ Easy
+ Minimal input from researcher

• Some bias as where the ad put ‘volunteer bias’ → more likely to show demand characteristics
• End up with people who are motivated to take part