Sampling Technique

Question 1

What is the sampling techniques?

Answer 1

Once researcher has identified the target population

Must identify the sample which they are going to use

Question 2

What is opportunity sampling?

Answer 2

People who are simply most available i.e. ones easiest to obtain

Ask people nearby

e.g students in class to take part of walk past you at shopping centre OR newspaper

Question 3

Advantages of opportunity sampling

Answer 3

• Quick method: convenient as you just make use of people who is closest. This makes one of the most popular sampling methods

Question 4

Disadvantages of opportunity sampling

Answer 4

Inevitably biased: Sampling is unrepresentative of target population as drawn from a specific area as one street in one town

Findings cannot be generalised

Question 5

What is volunteer sampling?

Answer 5

Self-selecting

In a volunteer sample , particpants will select themselves

They would advertise e.g place an ad in newspaper or noticeboard and particpant will come to you

Question 6

Advantages of volunteer sample

Answer 6

• Particpants are willing as they select themselves so know how much time and effort is involved - likely to engage more than people stopped in street

Question 7

Disadvantages of volunteer sampling

Answer 7

• Likely to be biased sample
• Particpants may share certain traits e.g keen and curious
• Generalistion limited due to volunteer bias

Question 8

What is random sample?

Answer 8

Equal chance: Every person in target population has an equal chance of being selected

How? Lottery method : All members of the target population are given a number and placed in hat

Question 9

Advantages of random sample

Answer 9

• Potentially unbiased: researcher has no influence over who is selected - free from researcher bias

Question 10

Disadvantage of random sample

Answer 10

• Representation not guranteed - Still possible that random method may produce biased sample - limited ability to generalise
• similar due to chance

Question 11

What is systematic sampling?

Answer 11

Sampling frame: Particpants are selected using a set ‘pattern’ (sampling frame)

How? Every nth person is selected from a list of target population

Question 12

Advantage of systematic sampling

Answer 12

• Unbiased -first time is usually selected at random. Objective method
• offers an unbiased representative sample

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Question 13

Disadvantage of systematic sampling

Answer 13

• Time and effort - A complete list of population is required as may as well use random sampling

Question 14

What is stratified sampling?

Answer 14

Freq: Particpants are selected according to their frequency in the target population

How? Subgroups (strata) are identified such as gender or age groups

Relative % of subroups in population are reflected in the sample

Question 15

Advantage of startified sample

Answer 15

Representative method - characteristic target population are represented. Generalisability are more likely than other methods

Question 16

What are the four main sampling technqiues?

Answer 16

• Opportunity
• Volunteer
• Random
• Syatematic
• Stratified

Question 17

Disadvantage of stratified sampling

Answer 17

• Startification is not perfect as strata cannot reflect all the ways in which people are different
• Complete representation is not possible

Question 18

What is the implications of sampling techniques?

Biases sampling

Answer 18

• Biased sample - Occurs when group selected for a statistical study is not random , therefore does not represent the target population - majority of samples are biased in that certain group may be over-under represented
• e.g random sampling - all female group by chance
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Question 19

What is the implications of sampling techniques?

Generalisation

Answer 19

• Generalization: tendency to respond in the same way to different but similar stimuli. - should be representative of population ( Ainsworth middle class white mothers , Asch - judgement test used all males in America)