Definition: Onetailed and twotailed test
Index: The Book of Statistical Proofs ▷ General Theorems ▷ Frequentist statistics ▷ Hypothesis testing ▷ Onetailed vs. twotailed
Sources:
Metadata: ID: D139  shortcut: testtail  author: JoramSoch  date: 20210331, 09:32.
Definition: Let there be a statistical test of an alternative hypothesis $H_1$ against a null hypothesis $H_0$. Then,

the test is called a onetailed test, if $H_1$ is a onetailed hypothesis;

the test is called a twotailed test, if $H_1$ is a twotailed hypothesis.
The fact whether a test is onetailed or twotailed has consequences for the computation of critical value and pvalue.
 Wikipedia (2021): "One and twotailed tests"; in: Wikipedia, the free encyclopedia, retrieved on 20210331; URL: https://en.wikipedia.org/wiki/One_and_twotailed_tests.
Metadata: ID: D139  shortcut: testtail  author: JoramSoch  date: 20210331, 09:32.