Increasingly, political scientists are describing their empirical research or the reasoning behind their choices in empirical research using the terms “experiment” or “experimental.” One of the primary reasons for doing so is the advantage of experiments in establishing causal inferences. In this book, Rebecca B. Morton and Kenneth C. Williams discuss in detail how experiments and experimental reasoning with observational data can help researchers determine causality. They explore how control and random assignment mechanisms work, examining both the Rubin causal model and the formal theory approaches to causality. They also cover general topics in experimentation such as the history of experimentation in political science; internal and external validity of experimental research; types of experiments – field, laboratory, virtual, and survey – and how to choose, recruit, and motivate subjects in experiments. They investigate ethical issues in experimentation, the process of securing approval from institutional review boards for human subject research, and the use of deception in experimentation. – Table of Contents : Part I. Introduction: 1. The advent of experimental political science. – Part II. Experimental Reasoning about Causality: 2. Experiments and causal relations; 3. The causal inference problem and the Rubin causal model; 4. Controlling observables and unobservables; 5. Randomization and pseudo-randomization; 6. Formal theory and causality. – Part III. What Makes a Good Experiment?: 7. Validity and experimental manipulations; 8. Location, artificiality, and related design issues; 9. Choosing subjects; 10. Subjects' motivations; 11. History of codes of ethics and human subjects research; 12. Ethical decision making and political science experiments; 13. Deception in experiments; 14. The future of experimental political science; 15. Appendix: the experimentalist's to do list.