Session 3 Randomization

3.1 Core content

  • What is randomization?

  • What is the difference between random assignment and random sampling?

  • What kind of control group do you need?

  • Four types of randomization: simple, complete, block, cluster.

  • How do you check whether your randomization “worked”?

  • Types of randomization designs
    • Factorial
    • Randomize access
    • Special focus: Randomize delay
    • Special focus: Encouragement
  • Limits to randomization (Threats)

3.2 Slides

Below are slides with the core content that we cover in our lecture on randomization. You can directly use these slides or make your own local copy and edit.

R Markdown Source

PDF version

html version

Slides from previous Learning Days

Randomization Lecture as used in Learning Days 10 Bogota

Lecture on Threats as used in Learning Days 11 Benin (first section reviews randomization designs)

3.4 Quizzes and Exercises

  • In-class exercise
    Doing replicable randomization in R

  • Sometimes different types of randomization are combined. Is it possible to do cluster randomization and then block randomized? Is it possible to do block randomization and then cluster randomization?

3.5 Examples

Examples of randomization designs by EGAP members