Database Reference
In-Depth Information
Figure 3.22
Distributions of two samples of data
The basic concept of hypothesis testing is to form an assertion and test it with
data. When performing hypothesis tests, the common assumption is that there is
no difference between two samples. This assumption is used as the default position
for building the test or conducting a scientific experiment. Statisticians refer to this
as the
null hypothesis
( ). The
alternative hypothesis
( ) is that there
is a difference between two samples. For example, if the task is to identify the
effect of drug A compared to drug B on patients, the null hypothesis and alternative
hypothesis would be this.
•
: Drug A and drug B have the same effect on patients.
•
: Drug A has a greater effect than drug B on patients.
If the task is to identify whether advertising Campaign C is effective on
reducing customer churn, the null hypothesis and alternative hypothesis
would be as follows.
•
: Campaign C does not reduce customer churn better than the current
campaign method.
•
: Campaign C does reduce customer churn better than the current
campaign.
