Measurement

• What is measurement in the context of psychology?

  The assignment of scores to individuals representing some characteristic
• What is psychometrics?


  The field of measurement in psychology
• What are examples of direct measurements in psychology?


  • Age
  • Brain weight
  • Heart rate
• What are examples of constructs that cannot be directly measured?


  • Extraversion
  • Intelligence
  • Depression
  • Pain levels
• What are psychological constructs?


  Summaries of complex sets of behaviours and internal processes
• What is an operational definition of a construct?


  It is precisely how the construct is to be measured
• What are the types of operational definitions for measuring constructs?


  1. Behavioural measures
  2. Self-report measures
  3. Physiological measures
• How is neuroticism operationally defined?


  As the mean response to 12 neuroticism items in the “Revised NEO Personality Inventory” measured online
• What are the levels of measurement in psychology?

  • **Nominal**: Name, putting people into categories
  • **Ordinal**: Some basis for ranking, uncertain gaps between levels
  • **Interval**: No true zero, gaps are evenly sized
  • **Ratio**: True zero