posted by Anonymous .
What are the major differences between pratical and statistical significance?
Statistical significance means the oberved mean differences are not likely due to dimpling error.
Practical significance looks at wether the difference is large enough to be of value in a practical sence.
For example, it is like adding an ingredient to a car's oil to improve the efficiency of the fuel. There is a need to have a careful controlled experiment by measuring the efficiency of the fuel before and afer introducing the additive. The findings of the experiment is that the difference is that the difference before and after has a statistcally significatly better, and come to the conclusion that the additive does improve the deficiency of the fuel. In the other hand the ingrdient has a cost of $100 a bottle, which effectives the savings in the efficiency of the fel. The diver does not really drive very much, so the conclusion is there is not much practically significant.
Does this sound like I am on the right path?
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