In statistical significance testing, a one-tailed test and a two-tailed test are alternative ways of computing the statistical significance of a parameter...

two-tailed p-values can be calculated as Φ(Z)(for lower/left-tailed tests), Φ(−Z) (for upper/right-tailed tests) and 2Φ(−|Z|) (for two-tailed tests) where...

Omnibus test One- and two-tailed tests One-class classification One-factor-at-a-time method One-tailed test – redirects to One- and two-tailed tests One-way...

location test of the null hypothesis such that the means of two populations are equal. All such tests are usually called Student's t-tests, though strictly...

Directed tests combine the attributes of one-tailed and two-tailed tests. "...directed tests should be used in virtually all applications where one-sided...

the one-tailed test above. In order to consider both the biases, we use a two-tailed test. Note that to do this we cannot simply double the one-tailed p-value...

the revised test statistic T−50. Using one of these sampling distributions, it is possible to compute either a one-tailed or two-tailed p-value for the...

the results of the tail flick test and it is important to consider this effect when performing the test. Lastly, many thermal tests do not distinguish...

t-distribution to test one of two possible null hypotheses: that the two population means are equal, in which a two-tailed test is applied; or that one of the population...

critical values for any given percentage point depend on: whether a one- or- two-tailed test is performed; the number of groups being compared; the overall...

between hind leg length and foreleg length. This is a two-tailed test, rather than a one-tailed test. For the two tailed test, the alternative hypothesis...

a pooled t-test or the Welch's t-test for two sample tests or analysis of variance or Welch's modified oneway ANOVA for multi-level tests. However, it...

if the population distributions are normal or are light-tailed and symmetric, then ANOVA F-test will generally have greater power which is the probability...

The tail suspension test (TST) is an experimental method used in scientific research to measure stress in rodents. It is based on the observation that...

of the test statistic and the hypotheses of interest about its distribution, different null hypothesis tests have been developed. Some such tests are the...

kstest and kstest2 for one-sample and two-sample Kolmogorov–Smirnov tests, respectively. The R package "KSgeneral" computes the KS test statistics and its...

unmistakable wedge-shaped tail, an elongated upper mandible, a strong beak and powerful feet. The wedge-tailed eagle is one of 12 species of large, predominantly...

Permutation, Parametric, and Bootstrap Tests of Hypotheses (3rd ed.). New York: Springer. Derrick, B; Ruck, A; Toher, D; White, P (2018). "Tests for equality of...

sample sizes. It is named after its inventor, Ronald Fisher, and is one of a class of exact tests, so called because the significance of the deviation from...

original example is termed a one-sided or a one-tailed test while the generalization is termed a two-sided or two-tailed test. The statement also relies...

various one-tailed and two-tailed versions of the test in the wilcoxon_test function. SciPy includes an implementation of the Wilcoxon signed-rank test in...

than by SNC. By December 2012, 15 full-scale tests had been successfully conducted, and additional ground tests continued into March 2013. In June 2012, the...

better. A two-tailed test may still be used but it will be less powerful than a one-tailed test, because the rejection region for a one-tailed test is concentrated...

on observations of the pairs. Chi-squared tests often refers to tests for which the distribution of the test statistic approaches the χ2 distribution asymptotically...

related. The rufous-tailed hawk, while comparatively little studied, is very similar to the red-tailed hawk, being about the same size and possessing the same...

essentially a V tail that extended both above and below the fuselage. The most popular conventionally V-tailed aircraft that has been mass-produced is the...

outlier. This table summarizes the limit values of the two-tailed Dixon's Q test. Grubbs's test for outliers Halpern, Arthur M. "Experimental physical...

X and Y from two populations, the probability of X being greater than Y is equal to the probability of Y being greater than X. Nonparametric tests used...

for one-sided right-tailed p-values; minor modifications can be made if two-sided or left-tailed p-values are being analysed. Specifically, if two-sided...

diverged from the ring-tailed lemur, making the group monophyletic and supporting the current two-genera taxonomy, or that the ring-tailed lemur is nested in...