Experimentwise error rate
Encyclopedia
In statistics
Statistics
Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....

, during multiple comparisons
Multiple comparisons
In statistics, the multiple comparisons or multiple testing problem occurs when one considers a set of statistical inferences simultaneously. Errors in inference, including confidence intervals that fail to include their corresponding population parameters or hypothesis tests that incorrectly...

 testing, experimentwise error rate is the probability of at least one false rejection of the null hypothesis
Null hypothesis
The practice of science involves formulating and testing hypotheses, assertions that are capable of being proven false using a test of observed data. The null hypothesis typically corresponds to a general or default position...

 over an entire experiment. The α (alpha) that is assigned applies to all of the hypothesis tests as a whole, not individually as in the comparisonwise error rate. In two or higher factorial ANOVAs the experimentwise error rate is higher than the familywise error rate
Familywise error rate
In statistics, familywise error rate is the probability of making one or more false discoveries, or type I errors among all the hypotheses when performing multiple pairwise tests.-Classification of m hypothesis tests:...

(error within a factor or interaction).
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK