This long awaited successor of the original Cook/Campbell "Quasi-Experimentation: Design and Analysis Issues for Field Settings" represents updates in the field over the last two decades. The book covers four major topics in field experimentation: Theoretical matters: Experimentation, causation, and validityQuasi-experimental design: Regression discontinuity designs, interrupted time series designs, quasi-experimental designs that use both pretests and control groups, and other designsRandomized experiments: Logic and design issues, and practical problems involving ethics, recruitment, assignment, treatment implementation, and attritionGeneralized causal inference: A grounded theory of generalized causal inference, along with methods for implementing that theory in single and multiple studies