Let . A value such that is considered ``significant'' (i.e., is not simply due to chance) is known as an Alpha Value. The Probability that a variate would assume a value greater than or equal to the observed value strictly by chance, , is known as a P-Value.
Depending on the type of data and conventional practices of a given field of study, a variety of different alpha values may be used. One commonly used terminology takes as ``not significant,'' , as ``significant'' (sometimes denoted *), and as ``highly significant'' (sometimes denoted **). Some authors use the term ``almost significant'' to refer to , although this practice is not recommended.
See also Alpha Value, Confidence Interval, P-Value, Probable Error, Significance Test, Statistical Test