Click on the following links. Please note these will open in a new window.

Research Methods Knowledge Base
Provides easy-to-understand explanations for several of the concepts in this chapter, including experimental designs, random assignment, internal validity, threats to validity, pre-test/post-test designs, etc. 

Teaching with Data
Provides many interactive resources to develop quantitative literacy.

Assessing Intervention Fidelity in RCTs: Concepts and Methods
Presentation from the Institute of Education Sciences Research Conference, which describes the practice of randomized control trials in education.