Lets Understand Null Hypothesis and Alternate Hypothesis.
Prerequisites:
part 1: What is Hypothesis Testing and When it is Used?
Null Hypothesis (H0) : It is a well Established Fact or An Assumption which treats everything is similar and equal.
Alternate Hypothesis(Ha) : The claim you want to prove.
Note: H0 and Ha are always opposite to each other.
https://keydifferences.com/
Example 1:
Statement: During 18th century, People used to believe that Sun revolves around the earth. Later Copernicus came and told that it is not true.
Since, At the time of 18th
century “Sun revolves around the earth” is a well established fact and is
widely accepted belief, So It will become our null hypothesis.
Copernicus claimed
that “Earth revolves around the sun” which is opposite to null hypothesis. So it
will become Alternate Hypothesis.
H0 : Sun revolves
around the Earth.
Ha : Earth revolves around the sun.
Example 2:
Statement: It is believed that a candy Machine makes chocolate bars that are on average 5g. a worker claims that the Machine after maintenance no longer makes 5g bars.
H0 : avg = 5 -> Given Fact about candy Machine.
Ha : avg != 5 -> Given Claim by the worker.
Example 3:
H0 : Model
B is not better than Model A.
Ha : Model B is better than Model A.
Here somehow if we
able to reject null hypothesis (well established fact) then Alternate
Hypothesis (new claim) will become established Truth.
Note: Since we can’t prove the new claim (Alternate Hypothesis) directly. We try to reject established fact(Null Hypothesis) using some evidence. This is the main idea behind Hypothesis Testing.
In the next blog, I will explain about how to conduct Hypothesis Testing and How to decide in rejection of Null Hypothesis.
part 3: Conducting Hypothesis Testing Step by Step - Easy and Elegant
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