Editing Null hypothesis (section)

{{short description|Position that there is no relationship between two phenomena}}
{{Technical|date=August 2021}}
{{Use dmy dates|date=March 2023}}
The '''null hypothesis''' (often denoted '''''H''<sub>0</sub>''')<ref>{{Cite web|url=https://www.thoughtco.com/definition-of-null-hypothesis-and-examples-605436|title=What Is the Null Hypothesis? Definition and Examples|last=Helmenstine|first=Anne Marie|website=ThoughtCo|language=en|access-date=10 December 2019}}</ref> is the claim in [[Research|scientific research]] that the [[Effect size|effect]] being studied does not exist.{{NoteTag|Note that the term "effect" here is not meant to imply a causative relationship.|name=abc}}  The null hypothesis can also be described as the hypothesis in which no relationship exists between two sets of data or variables being analyzed. If the null hypothesis is true, any experimentally observed effect is due to chance alone, hence the term "null". In contrast with the null hypothesis, an [[alternative hypothesis]] (often denoted '''''H''<sub>A</sub>''' or '''''H''<sub>1</sub>''')<ref>{{Cite web|url=https://www.thoughtco.com/definition-of-null-hypothesis-and-examples-605436|title=What Is the Null Hypothesis? Definition and Examples|last=Helmenstine|first=Anne Marie|website=ThoughtCo|language=en|access-date=10 April 2025}}</ref> is developed, which claims that a relationship does exist between two variables.