The nonparametric Wilcoxon Rank Sum (also known as the Mann-Whitney U) and the permutation t-tests are robust with respect to Type I error for departures from population normality, and both are powerful alternatives to the independent samples Student's t-test for detecting shift in location. The question remains regarding their comparative statistical power for small samples, particularly for n...

The purpose of this study is to elicit problem causing word stress patterns for Turkish EFL (English as a foreign language) learners and investigate whether Internet-based pronunciation lesson is superior to traditional pronunciation lesson in terms of enhancing Turkish EFL learners’ accurate production of stressed syllables in English words. A pre-post test design with two groups of Turkish EF...

h. t-Test: This is one of the most powerful and widely used statistical tests. The ttest (Student's t) is used to calculate the confidence intervals of a measurement when the population standard deviation ()) is not know. Which is usually the case. The t-test is also used to compare two averages. The t-test corrects for the uncertainty of the sample standard deviation (s) caused by taking a sma...

• ‘Student’ was a statistician who worked in quality control. • The t test asks ‘how probable are these samples, if they have been sampled from the same source?’ • Considering what would be found when repeated samples are taken is the frequentist approach to statistical testing. • ‘Student’s t test does not indicate the probability that the null hypothesis is true. • Other methods of testing ex...

In statistic tests, the probability distribution of the statistics is important. When samples are drawn from population N (µ, σ(2)) with a sample size of n, the distribution of the sample mean X̄ should be a normal distribution N (µ, σ(2)/n). Under the null hypothesis µ = µ0, the distribution of statistics [Formula: see text] should be standardized as a normal distribution. When the variance of ...

The Student’s t Test. A very common problem in statistics is to estimate the population mean of a probability distribution given a sample, the subject of sections 7.1 and 7.2 of the statistics textbook. As explained there, this relates directly to the so-called t test. For large samples we may assume, due to the central limit theorem, that the sample mean is normally distributed; one often cons...

This report describes the evaluation of a chemical test for T-antigen in rectal mucus as a screening test for colon cancer. The test, called the Mucus Strip Test, detects the disaccharide residue sialic acid-free beta-D-Gal(1-->3)-D-GalNAc or T-antigen, which accumulates in mucus from malignant cells and colonic mucosa adjacent to cancer but not in normal mucosa. Participants were an unselected...