Choosing Statistical Tests

Choosing statistical tests: part 12 of a series on evaluation of scientific publications.

BACKGROUND The interpretation of scientific articles often requires an understanding of the methods of inferential statistics. This article informs the reader about frequently used statistical tests and their correct application. METHODS The most commonly used statistical tests were identified through a selective literature search on the methodology of medical research publications. These tes...

Statistical tests

Error in statistical tests of error in statistical tests

BACKGROUND A recent paper found that terminal digits of statistical values in Nature deviated significantly from an equiprobable distribution, indicating errors or inconsistencies in rounding. This finding, as well as the discovery that a large percentage of p values were inconsistent with reported test statistics, led to a great deal of concern in the popular press and scientific community. Th...

Choosing Color Palettes for Statistical Graphics

Statistical graphics are often augmented by the use of color coding information contained in some variable. When this involves the shading of areas (and not only points or lines)— e.g., as in bar plots, pie charts, mosaic displays or heatmaps—it is important that the colors are perceptually based and do not introduce optical illusions or systematic bias. Here, we discuss how the perceptually-ba...

Notes on statistical tests ∗

Let an unbiased coin be used to form an ω-sequence S of independent tosses. Let N be the positive integers. The finite initial segment of length n ∈ N is denoted by Sn (thus, S1 holds exactly the first toss). For n ∈ N , let Hn be the proportion of heads that show up in Sn. Pick a positive real number D, to be thought of as a number of standard deviations from the mean of the standard normal di...