Sampling_Techniques

Question 1

Explain investigator affects

Answer 1

• Expectancy effects/subconcious cues affect how participants are treated, confounds results
• Bias in creating the study’s design

Question 2

How do you obtain a random sample?

Answer 2

• Obtain list of target population
• Number them, randomly generate numbers

Question 3

Evaluate random samples

Answer 3

• Due to probability should be unbiased
• List is difficult to obtain
• Possibility of it still being biased
• Participants ay refuse, creating bias

Question 4

How do you obtain a systematic sample?

Answer 4

• Every nth member selected, start at random point in list
• List organised alphabetically for example

Question 5

Evaluate systematic samples

Answer 5

• Objective, no researcher bias
• Time consuming
• Participants may refuse, creating bias

Question 6

How do you obtain a stratified sample?

Answer 6

• Identify subgroups (strata) and their proportions
• Randomly select from proportions of each strata

Question 7

Evaluate stratified samples

Answer 7

• Representative of target population, therefore able to generalise
• Cannot reflect all individuals (participant variables)
• Not economical

Question 8

How do you obtain an opportunity sample?

Answer 8

Whoever is willing and available at the time (i.e. on the street)

Question 9

Evaluate opportunity samples

Answer 9

• Economical, little effort required
• Unrepresentative of target population
• Researcher bias as they choose people

Question 10

How do you obtain a volunteer sample?

Answer 10

Study is advertised, participants self-select

Question 11

What are the limitations of case studies?

Answer 11

• Cannot generalise findings
• Subjective interpretations of researcher, subjective sources of information

Question 12

What is discussed in the ‘method’ section of a report of a psychological investigation?

Answer 12

• Experimental design
• Sample (sampling, target population, etc)
• Apparatus/materials
• Procedure
• Explanation of ethics