Sampling

Question 1

Population

Answer 1

The large group of people that a researcher is interested in studying, for example college students from the North West.

Question 2

Sample

Answer 2

It is usually not possible to include all members of the population in the study, so a smaller group is selected- the sample.

Question 3

Generalisation

Answer 3

The sample that is drawn should be representative of the population so generalisations can be made.

Question 4

Bias

Answer 4

Most samples are biased in that certain groups may be over- or under- represented.

Question 5

Random Sample

Answer 5

-Every person in the target population has an equal chance of being selected.
-Lottery methods- all members of the target population are given a number and placed in a hat or computer/phone randomiser used.

Question 6

A03 (+)

Answer 6

P- Potentially unbiased
E- This means CV’s/EV’s are controlled
E- Enhances internal validity

Question 7

A03 (-)

Answer 7

P- Time consuming and may not work
E- Complete list of population is hard to get
E- Also some participants may refuse to take part

Question 8

Systematic Sampling

Answer 8

-Participants are selected using a set ‘pattern’
-Every nth person is selected from a list of the target population

Question 9

A03 (+)

Answer 9

P- Unbiased
E- The first item is usually selected at random
E- Objective Method

Question 10

A03 (-)

Answer 10

P- Time and effort
E- A complete list of the population is required
E- May as well use random sampling

Question 10

Stratified Sample

Answer 10

-Sample reflects proportions of people in certain subgroups within a population.
-Subgroups are identified. The relative percentages of the subgroups in the population are reflected in the sample.

Question 11

A03 (+)

Answer 11

P- Representative Method
E- The characteristics of the target population are represented
E- Generalisability more likely than other methods

Question 12

A03 (-)

Answer 12

P- Stratification is not perfect
E- Strata cannot reflect all the ways in which people are different.
E- Complete representation is not possible

Question 13

Opportunity Sample

Answer 13

-People who are simply most available
-Ask people nearby

Question 14

A03 (+)

Answer 14

P- Quick method
E- Opportunity sampling is convenient because you just make use of the people who are closest.
E- This makes it cheaper and one of the most popular sampling methods

Question 15

A03 (-)

Answer 15

P- Inevitably biased
E- The sample is unrepresentative of the target population as it is drawn from a very specific area, such as one street in one town
E- This means that the findings cannot be generalised

Question 16

Volunteer Sample

Answer 16

-In a volunteer sample, participants select themselves
-Advertise. For example, place an advert in a newspaper or ask people to put hands up to volunteer

Question 17

A03 (+)

Answer 17

P- Participants are willing
E- Participants have selected themselves and know how much time and effort is involved
E- Likely to engage more than people stopped in the street

Question 18

A03 (-)

Answer 18

P- Volunteer bias
E- Participants may share certain traits
E- Respond to cues and generalisation limited