Scientific processes (Sampling)

Question 1

Population

Answer 1

A group of people who are the focus of the researchers interest, from which a smaller sample is drawn

Question 2

Sample

Answer 2

A group of people who take part in a research investigation. The sample is drawn from a (target) population and is presumed to be representative of that population

Question 3

Sampling techniques

Answer 3

Psychologists use sampling techniques to choose people to represent the target population

Question 4

Random sampling

Answer 4

Every member of the target population has an equal chance of being selected
eg. pulling name out of a hat/ name generator

Question 5

Strength of random sampling

Answer 5

• Free from researcher bias

Question 6

Limitation of random sampling

Answer 6

• Difficult and time consuming (individuals may be unwilling to take part)

Question 7

Systematic sampling

Answer 7

A predetermined system is used to select participants

Eg. every fifth person is chosen

Question 8

Strength of systematic sampling

Answer 8

• Free from researcher bias (not selecting)

Question 9

Limitation of systematic sampling

Answer 9

• Not truely unbiased, every fifth person may have the same characteristic eg. right handed

Question 10

Stratified sampling

Answer 10

Subgroups within a population are identified

Question 11

Strength of stratified sampling

Answer 11

• Free from researcher bias (subgroups are identified)

Question 12

Limitation of stratified sampling

Answer 12

Difficult to ensure the subgroups in target population are all identified (time consuming)

Question 13

Opportunity sampling

Answer 13

Selecting anyone who is available and willing to take part in the study at the time

Question 14

Strength of opportunity sampling

Answer 14

• Quicker and easier and requires less effort from researcher

Question 15

Limitation of opportunity sampling

Answer 15

• Researcher has complete control over who they approach

Question 16

Volunteer sampling

Answer 16

Consists of participants self-selecting to take part in a study be either volunteering when asked or respond to an advert

Question 17

Strength of volunteer sampling

Answer 17

• Participants approach the research; less effort and mens it will be quicker and easier

Question 18

Disadvantage of volunteer sampling

Answer 18

• Particular people who want to be involved; biased and not representative of target population