Lecture 4: Sampling and Measurement

Question 1

What is population?

Answer 1

entire group of people of interest

Question 2

What is a sample?

Answer 2

smaller group of people who complete study procedures

Question 3

What are representative samples?

Answer 3

sample should be similar enough to the population to make generalizable conclusions

Question 4

How can you have more representative samples?

Answer 4

• sampling technique
• larger samples
• breadth of recruitment

Question 5

What are different sampling techniques?

Answer 5

probability sampling and non-probability sampling

Question 6

What is probability sampling?

Answer 6

all members of the population have a known probability (chance) of being selected for the sample
- more likely to result in a representative sample

Question 7

What is non-probability sampling?

Answer 7

there is no real effort to ensure that sample accurately represents population
- less likely to result in representative sample on their own

Question 8

What are the general approaches to measurement?

Answer 8

• self-report measures
• behavioural measures
• physiological measures

Question 9

How do you choose a measure?

Answer 9

• nature of operalization & research question/hypothesis
• cost
• quality (reliability, validity, reactivity)

Question 10

What is reliability?

Answer 10

how consistently a measure measures a particular variable

Question 11

What are the different types of reliability?

Answer 11

• internal consistency
• test-retest reliability
• inter-rater reliability

Question 12

What is internal consistency?

Answer 12

how consistent is the measure across items measuring the same concept

Question 13

What is test-retest reliability?

Answer 13

how consistent is the measure across time points

Question 14

What is inter-rater reliability?

Answer 14

how consistent is the measure across different raters

Question 15

What is validity?

Answer 15

how well a measure measures the variable it is intended to measure

Question 16

What are the different indicators of construct validity?

Answer 16

• face validity
• content validity
• predictive validity
• concurrent validity
• convergent validity
• discriminant validity

Question 17

What is face validity?

Answer 17

measure appears to measure the construct of interest

Question 18

What is content validity?

Answer 18

measure captures necessary aspects of construct, nothing more

Question 19

What is predictive validity?

Answer 19

extent to which scores on the measure predict related criteria measured later

Question 20

What is concurrent validity?

Answer 20

extent to which scores on the measure are related to another relevant variable measured at the same time

Question 21

What is convergent validity?

Answer 21

extent to which scores on the measure are related to other measures of the same/similar constructs

Question 22

What is discriminant validity?

Answer 22

demonstration of scores on the measure being unrelated to measures that are not conceptually related to the construct

Question 23

What is reactivity?

Answer 23

the degree to which participants’ behaviours/responses change as a result of measurement

Question 24

What are issues of reactivity in self-reports?

Answer 24

• participant may deny being stressed in the interest of appearing “tough” or “strong”
• participant may also exaggerate their stress reaction if they thought they may have something to gain from it

Question 25

How do you minimize issues of reactivity in self-reports?

Answer 25

• remind participants to be as honest as possible
• anonymous data collection

Question 26

What are issues of reactivity in behavioural measures?

Answer 26

• participant may be more nervous knowing they’re being observed so might display more stress behaviours than usual
• participant may hide stress

Question 27

How do you minimize issues of reactivity in behavioural measures?

Answer 27

• give time under observation
• use naturalistic observation or deception

Question 28

What issues of reactivity in physiological measures?

Answer 28

• physiological reactions may be exaggerated simply by them being measured

Question 29

How do you minimize issues of reactivity in physiological measures?

Answer 29

have a longer baseline where participant is connect to get comfortable being attached to machines