# Whether a problem is a one sided test or a two sided test

Could you explain when and why one would use a one sided test vs a two sided test; I am confused about what "drives" the selection of one type over the other?

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The choice of one-sided or two-sided test depends on the form of alternative hypothesis. If the alternative hypothesis is in the form , we have to use two-sided test. On the other hand, if the alternative hypothesis is either in the form or form, we have to use one-sided test.

To provide a detailed explanation, first I will provide the five steps of a test procedure, known as five-step procedure.

Step1. Specify the null hypothesis H0 and alternative hypothesis H1. The null hypothesis is the hypothesis that the researcher formulates and proceeds to test. If the null hypothesis is rejected after the test, the hypothesis to be accepted is called the alternative hypothesis.

Step2. Specify the significance level (). The significance level of a test is the probability of rejecting a null hypothesis when it is true. A test is to be constructed in such a manner that the probability of committing this error (Type I error) a pre ...

#### Solution Summary

This solution helps determine whether a problem is a one-sided or two-sided test.