This document provides an overview of quantitative method design, specifically experimental design. It discusses key concepts in experimental design including random assignment, control over extraneous variables, manipulation of treatment conditions, outcome measures, and threats to validity. It also describes different types of experimental designs including between-group designs like true experiments, quasi-experiments, and factorial designs as well as within-group designs like time series experiments, repeated measures experiments, and single subject experiments. The document provides examples and explanations of how to implement these different experimental designs.