Reliability & Validity

Reliability & Validity

Reliability = Does it provide a consistent result (even if it is wrong)

Validity = Does it measure what it says it measures

Reliability

Inter Observer

Test Retest

Parallel Forms

Split Half

Internal Validity

History Maturation Testing Instrumentation Mortality Statistical Regression to the Mean Social Interaction Diffusion of Treatment & Compensatory Rivalry Resentful Demoralization & Compensatory

Equalization

External Validity- Generalizability

Lab vs Field Studies and other setting issues

Selection Bias Pretest Multiple Treatment Reproduction Issues

Construct Validity

Inadequate Preoperational Explication Mono-Operation Bias Mono-Method Bias Interaction of Different TXs Interaction of testing and Tx Restricted Generalizability across Constructs Confounding/Levels Hypothesis Guessing Evaluation Apprehension Experimenter’s Expectations and Demand

Characteristics

Measurement Validity

Face Validity Content Criterion Predictive Concurrent Construct Discriminant

Statistical Conclusion Validity

Statistical Significance

Remember Type I and Type II Errors?