Establishing a Cause-Effect Relationship

Internal Validity What you did and what you sawWhat you did and what you saw Your program and your observationsYour program and your observations Observation ProgramObservations What you do What you see Is the relationship causal between... Alternativecause Alternativecause Alternativecause Alternativecause In this study program-outcome relationship

Establishing Cause and Effect Temporal precedence

Establishing Cause and Effect Temporal precedence CauseEffect then Time

Establishing Cause and Effect Temporal precedence CauseEffect then Time Why is this important?

Establishing Cause and Effect Temporal precedence CauseEffect then Time Why is this important? Cyclical functions Inflation Unemployment

Establishing Cause and Effect Temporal precedence Covariation of cause and effect CauseEffectthen Time

Establishing Cause and Effect Temporal precedence Covariation of cause and effect CauseEffectthen time if X, then Y if not X, then not Y

Establishing Cause and Effect Temporal precedence Covariation of cause and effect CauseEffectthen Time if X, then Y if not X, then not Y if program given, then outcome observed if program not given, then outcome not observed

Establishing Cause and Effect Temporal precedence Covariation of cause and effect CauseEffectthen Time if X, then Y if not X, then not Y if program given, then outcome observed if program not given, then outcome not observed if more of program, then more of outcome observed if less of program given, then less of outcome observed

Establishing Cause and Effect Temporal precedence Covariation of cause and effect No alternative explanations CauseEffectthen Time if X, then Y if not X, then not Y

Establishing Cause and Effect Temporal precedence Covariation of cause and effect No alternative explanations CauseEffectthen Time if X, then Y if not X, then not Y ProgramOutcome Causes?

Establishing Cause and Effect Temporal precedence Covariation of cause and effect No alternative explanations CauseEffectthen Time if X, then Y if not X, then not Y ProgramOutcome Causes? Alternativecause Alternativecause Alternativecause Alternativecause

In Typical Outcome Evaluation... l Is taken care of because you intervene before you measure outcome l Is taken care of because you control the intervention l Is the central issue of internal validity -- usually taken care of through your design Temporal precedence Covariation of cause and effect No alternative explanations