Chapter 5: Identifying good measurement Flashcards
3 types of measure
- self-report measure
- observational measure
- physiological measure
self-report measure
operationalizes a variable by recording people’s answers to questions about themselves in a questionnaire or interview
observational measure
operationalizes a variable by recording observable behavior or physical traces of behavior
physiological measure
operationalizes a variable by recording biological data
quantitative (continuous) variables
coded with meaningful numbers
- ordinal scale
- interval scale
- ratio scale
ordinal scale
applies when the numerals of a quantitative variable represent a ranked order with scales that might be unequal
interval scale
applies to the numerals of a quantitative variable that meet 2 conditions
- the numberals represent equal intervals between levels
- there is no true 0 (a person can score 0, but it does not mean literally nothing)
ratio scale
applies to the numerals of a quantitative variable under 2 conditions
- the numerals represent equal intervals between levels
- there is a true 0, a person is able to score 0 and that means literally nothing
reliability vs validity
- reliability: how consistent the results of a measurement are
- validity: is the operationalization measuring what it is supposed to measure
test-retest reliability
a study participant will get pretty much the same score each time they are measured with it
interrater reliability
consistent scores are obtained no matter who measures the variable
internal reliability
a study participant gives a consistent pattern of answers, no matter how the researchers phrase the question
average inter-item correlation (AIC)
the average of all correlations
cronbach’s alpha
combines the AIC and the number of items in a scale
- the closer it is to 1 the better the reliability of the scale is
- for self-report measures: 0.8+
types of reliability relevant for each kind of the three operationalizations