 
Summary: Math 140
Introductory Statistics
Professor Bernardo Ábrego
Lecture 25
Sections 8.2, 8.3
Types of Error
There are two possible types of error in
significance testing:
CorrectType I errorReject H0
Type II errorCorrectDon't Reject H0
FalseTrue
Null hypothesis is actually
Your
decision
Type I error
(When Test Statistic is Large)
If the test statistic is large in absolute value (like Miguel and
Kevin's example), then the possible explanations for this are:
1. The null hypothesis is true and a rare event occurred. That
is, it was just bad luck that resulted in being so far from p0.
