# HStatistics.com

### Types of Errors

In this post we would look at the Types of Errors in Hypothesis testing.

There are two types of errors that you might make in the hypothesis testing process: type-I error and type-II error.

A type I-error, represented by α, occurs when you reject a true null hypothesis.

ie. You shouldnt have rejected the null hypothesis, yet you rejected it.

A type-II error, represented by β, occurs when you fail to reject a false null hypothesis.

ie. You should have rejected the null hypothesis when you failed to reject it.

As showcased in the image below:

For example,

In a criminal trial example, if the jury convicts the accused even on less substantial evidence.

Then they are more likely to make type 1 error.

The probability of a type-I error can be reduced if the jury follows more stringent criteria to convict an accused party.

However, reducing the probability of a type-I error may increase the probability of making a type-II error.

If the jury becomes very liberal in acquitting people on trial, there is a higher probability of an actual criminal walking free.

As showcased in the image below: