William Roberts Clark is the author of Capitalism, Not Globalism; Principles of Comparative Politics; and numerous journal articles. With Sona and Matt Golder he was awarded the Brian Barry Prize by the British Academy. He has taught at six leading research universities and is currently President of the European Political Science Association. Matt Golder is in the top 2 per cent of the most cited scientists worldwide, and his article with William Clark, 'Understanding Interaction Models: Improving Empirical Analyses' is in the top 10 most cited articles in political science (http://charlesbreton.ca/assets/PS_Top10_2020.pdf). He is the winner of the GESIS Klingemann Prize and the Brian Barry Prize from the British Academy.

• 1. Introduction; Part I. The Fundamentals: 2. Theories and their conditional implications; 3. Interaction model specification; 4. Interpreting quantities of interest: effects, predicted values and measures of uncertainty; 5. Three substantive applications: interpretation and presentation; Part II. More Complex Forms of Conditionality: 6. When we have more than one modifying variable; 7. When an independent variable interacts with itself; Part III. Interactions and Limited Dependent Variables: 8. Interactions and dichotomous dependent variables; 9. Interactions and ordered dependent variables; 10. Interactions and unordered dependent variables; Appendices.

William Roberts Clark is the author of Capitalism, Not Globalism; Principles of Comparative Politics; and numerous journal articles. With Sona and Matt Golder he was awarded the Brian Barry Prize by the British Academy. He has taught at six leading research universities and is currently President of the European Political Science Association. Matt Golder is in the top 2 per cent of the most cited scientists worldwide, and his article with William Clark, 'Understanding Interaction Models: Improving Empirical Analyses' is in the top 10 most cited articles in political science (http://charlesbreton.ca/assets/PS_Top10_2020.pdf). He is the winner of the GESIS Klingemann Prize and the Brian Barry Prize from the British Academy.

• 1. Introduction; Part I. The Fundamentals: 2. Theories and their conditional implications; 3. Interaction model specification; 4. Interpreting quantities of interest: effects, predicted values and measures of uncertainty; 5. Three substantive applications: interpretation and presentation; Part II. More Complex Forms of Conditionality: 6. When we have more than one modifying variable; 7. When an independent variable interacts with itself; Part III. Interactions and Limited Dependent Variables: 8. Interactions and dichotomous dependent variables; 9. Interactions and ordered dependent variables; 10. Interactions and unordered dependent variables; Appendices.

William Roberts Clark is the author of Capitalism, Not Globalism; Principles of Comparative Politics; and numerous journal articles. With Sona and Matt Golder he was awarded the Brian Barry Prize by the British Academy. He has taught at six leading research universities and is currently President of the European Political Science Association. Matt Golder is in the top 2 per cent of the most cited scientists worldwide, and his article with William Clark, 'Understanding Interaction Models: Improving Empirical Analyses' is in the top 10 most cited articles in political science (http://charlesbreton.ca/assets/PS_Top10_2020.pdf). He is the winner of the GESIS Klingemann Prize and the Brian Barry Prize from the British Academy.

• 1. Introduction; Part I. The Fundamentals: 2. Theories and their conditional implications; 3. Interaction model specification; 4. Interpreting quantities of interest: effects, predicted values and measures of uncertainty; 5. Three substantive applications: interpretation and presentation; Part II. More Complex Forms of Conditionality: 6. When we have more than one modifying variable; 7. When an independent variable interacts with itself; Part III. Interactions and Limited Dependent Variables: 8. Interactions and dichotomous dependent variables; 9. Interactions and ordered dependent variables; 10. Interactions and unordered dependent variables; Appendices.