Magic of randomness: causality
Learning objectives
- Recognize and know the elements of a designed randomized experiment.
- State and apply the Four Principles of Experimental Design.
- Control sources of variation other than the factors being tested. Make the condi- tions as similar as possible for all treatment groups except for differences among the treatments.
- Randomize the assignment of participants to treatments.
- Replicate by applying each treatment to more than one participant.
- Block the experiment by grouping together participants who are similar in important ways that you cannot control.
- Work with blinding and control groups.
- Be alert for possible confounding due to a variable that is not under control affecting the responses differentially.