Sampling (AO1 + AO3)

Question 1

Population

Answer 1

refers to the large group of individuals that a researcher may be interested in studying. often called the target population bc it is a subset of the general population

Question 2

Sample

Answer 2

a smaller group of people drawn from the target population
- aimed to be representative so results can be generalised

Question 3

5 Types of Sampling

Answer 3

random sample
systematic sample
stratified sample
opportunity sample
volunteer sample

Question 4

Random Sample

Answer 4

gives every member of the target population an equal chance of being selected
- identify all members of target pop.
- assign all names a number/ put in a hat
- generate sample using lottery method (random number generator/pull names out of a hat)

Question 5

Positives of Random Sample

Answer 5

• likely to be representative so can be generalised
• free from researcher bias

Question 6

Negatives of Random Sample

Answer 6

• difficult + time consuming to get full details of target pop.
• selected ppl may be unwilling to take part
• may still be unrepresentative due to randomness

Question 7

Systematic Sample

Answer 7

selecting every nth person of the target pop. (e.g. every 3rd person on the register)
- identify all members if the target pop.
- organise into order (e.g. alphabetic)
- choose interval + apply consistently (e.g. every 3rd person)

Question 8

Positives of Systematic Sample

Answer 8

• free from researcher bias

Question 9

Negatives of Systematic Sample

Answer 9

• could be unrepresentative, every nth person may share characteristics

Question 10

Stratified Sample

Answer 10

when the sample represents the proportions of people in sub-groups within the target pop.
(e.g. 40% girls in sixth-form, the sample must have 40% girls too)
- identify subgroups (strata) withing population
- obtain ppts in proportion to population

Question 11

Positives of Stratified Sample

Answer 11

• most likely to be representative
• results can be generalised
• avoids researcher bias

Question 12

Negatives of Stratified Sample

Answer 12

• difficult + time consuming
• selected ppl may be unwilling to take part
• complete representation unachievable bc multiple strata

Question 13

Opportunity Sample

Answer 13

selecting anyone who is available + willing to take part in the study - whoever is around at the time
- just select ppts who are willing to take pat
- e.g. stand in a public place and ask whoever passes by

Question 14

Positives of Opportunity Sample

Answer 14

• quicker + easier

Question 15

Negatives of Opportunity Sample

Answer 15

• high chance sample will be biased (often uni students)
• researcher bias
• therefore unrepresentative

Question 16

Volunteer Sample

Answer 16

ppts select themselves to be part of the sample - also referred to as self selection
- ppts usually respond to an advert/offer to take part

Question 17

Positives of Volunteer Sample

Answer 17

• quicker + easier

Question 18

Negatives of Volunteer Sample

Answer 18

• particular type of person likely to take part (volunteer bias)
• cant necessarily generalise