Class #6: Measuring Behavior

1. Measures of Variance:

• Observational
• Physiological
• Self-Report
  Converging operations: Using multiple methods to measure variance

2. Measurement Scales
-Nominal variables
-Continuous variables: Ordinal, Interval, Ratio

3. Observed Score = True score 🙂 + Measurement Error 😦

We want to minimize measurement error, but things happens:

• Transient Participant State (e.g. mood)
• Stable Attributes  (e.g. personality)
• Situational Factors (e.g. noisy environment)
• Characteristics of the Measure (e.g. question in another language)
• Mistakes (e.g. equipment malfunction)

4. Reliability: the consistency or dependability of a measuring technique (e.g. Test-Retest, Inter-item…)
Reliability = True Score Variance / Total Variance
(Higher reliability = lower mesurement error)

5. Validity: The extent to which a measurement procedure measures what it is intended to measure rather than measuring something else (or nothing at all)
e.g. Measuring your own values using random people’s comments: Not valid!

Bonus: A measure can be reliable, but not valid. However, a valid measure is probably reliable.