Construct Validity 

• 
  Subsumes all types of validity
• 
  Determines the appropriateness of inferences about a construct 
• Hypothesize a pattern of relationships between the test scores and scores on another variable. 
• 
  Then, test the hypotheses

Construct

a collection of related behaviors that are associated in a meaningful way

Depression: A Construct

• 
  The construct itself does not have a physical being outside of its indicators.
• Thus, we infer its existence by observing the collection of related indicators (behaviors). 
• Emphasis on collection crucial because any one sign may be associated with several constructs.