sampling techniques

Question 1

random sampling

Answer 1

a sophisticated method of ensuring all members of target population have an equal chance of being selected

Question 2

systematic sampling

Answer 2

when every nth member of the target population is selected using a sampling frame

Question 3

systematic sample method

Answer 3

1. sampling frame produced. list of people in target population organised e.g. alphabetical order
2. sampling system nominated (every 3rd, 6th, 8th person etc.) or interval determined randomly to reduce bias
3. researcher works through sampling frame until sample complete

Question 4

stratified sampling

Answer 4

a sophisticated method of ensuring that the composition of the sample reflects the proportions of people in certain sub-groups within the target population

Question 5

stratified sample- method

Answer 5

1. researcher identifies different strata that makes up target population
2. proportions needed for sample to be representative calculated
3. participants that make up each stratum selected using random sampling

Question 6

opportunity sampling

Answer 6

people selected based on availability and willingness

Question 7

volunteer sampling

Answer 7

participants select themselves to be part of the sample

Question 8

random sample- strengths

Answer 8

• no researcher bias. no influence over who is selected so can’t choose those they think would support hypothesis.

Question 9

random sample- weaknesses

Answer 9

• difficult and time-consuming. complete list of target population difficult to obtain.
• still may have unrepresentative sample (probability- still more representative than opportunity sampling)
• selected participants may refuse

Question 10

systematic sample- strengths

Answer 10

• avoids researcher bias. once selection sample established no influence.
• usually fairly representative.

Question 11

stratified sample- strengths

Answer 11

• avoids researcher bias. once sub-divided into strata, randomly selected numbers no influence
• representative sample, accurately reflects composition of population. generalisation of findings.

Question 12

stratified sample- weaknesses

Answer 12

identified strata cannot reflect all ways that people are different. complete representation of target population not possible.

Question 13

opportunity sample- strengths

Answer 13

• less time-consuming and more economical

Question 14

opportunity sampling- weaknesses

Answer 14

• sample unrepresentative of target population. drawn from specific area.
• researcher bias. complete control over selection.

Question 15

volunteer sample- strengths

Answer 15

less time-consuming, requires minimal input from researcher

Question 16

volunteer sample- weaknesses

Answer 16

volunteer bias. asking for volunteers may attract certain ‘profile of person’- more helpful, keen, curious, etc. affects generalisability.