Research, Rapid Research Review

Rapid Research Review: Type of Error

Term: Type of Error

Type I and Type II Errors and alpha and beta. These terms are basic for statisticians, but they can be quite confusing to those who do not use them frequently. Am I not not rejecting the null hypothesis? Is that a triple negative?

There is a high likelihood that a question related to this topic will appear on your board exams. The chart below hopefully provides a helpful guide for the non-researcher.

Note that “alpha” or “α” is used to signify the risk of a Type I error allowed by researchers. The actual chance that this error would occur is what we are familiar with as a “p value." A “p value” is a result after the study is done, while α is determined by the researchers prior to any data collection.

“Beta” or “β” is the risk of a type 2 error. It is related to the “power” of a study such that 1- β = power.

Typical numbers accepted in medical studies are α of 0.05 and β of 0.2. We generally accept not finding that something works when it actually might slightly more than saying something works when it doesn’t. Several factors contribute to this in practice, but the most important one is sample size, or the number of patients in a study.

Related Articles

Rapid Research Review: More Study Types

EM Resident 02/02/2017
Rapid Research Review: More Study Types More Study Types Case Series This is used when the objective is to describe and find patterns related to a particular disease/problem. Case series are useful f

Journal Club for Dummies: How Not to Be Intimidated by Evidence-Based Medicine

Journal Club for Dummies: How Not to Be Intimidated by Evidence-Based Medicine Have you ever looked at a journal club article and felt overwhelmed? You are not alone! Many residents are in the same b
CHAT NOW
CHAT OFFLINE