# Randomization in clinical trials

In some phase 2 and all phase 3 clinical trials, patients are assigned to groups that receive different treatments. The process of assigning patients to these groups by chance is called randomization. Learn how researchers randomly assign clinical trial participants to different treatment groups in order to prevent bias in the results.

- Kind: Short
- Year: 2019
- Runtime: 1 min
- By: National Cancer Institute
- Archive: [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Randomization_in_clinical_trials.webm)
- Licence or status: Public domain (as the archive states it)
- Credit: National Cancer Institute
- Who can watch: Teens profiles and older (the archive gives no rating; placed by Invisible Network from its collection and subjects)

[Watch now](https://invisiblenetwork.ai/watch/archive/commons/99581397?play=1)