There are many issues that researchers need to address in computing treatment effects, many of which have not been tackled thus far in the literature. This book comprehensively addresses all the relevant issues in computing treatment effects, including many not previously detailed in the literature. It examines the relations between the different kinds of treatment effects, and how to convert amongst them, detailing both correlational and continuous data. Introductions and worked examples are provided for all the formulas used and an accompanying website with an instructional version of a computer program that computes treatment effects, allows the reader to perform all the exercises in the book, and check the accuracy of any spreadsheets they constructed.