Purpose

nhstplot is a simple and convenient package to represent graphically the most common Null Hypothesis Significance Tests (NHST).

In other words, it plots the density functions of z, t, F and Chi-squared, adding a cutline at the observed statistic value, scaling it all conveniently, and plotting a label for the p value.

How to use it

First, install the library with install.packages("nhstplot"), load the library with library(nhstplot).

nhstplot is composed of 4 functions, one for each major NHST test “family” :

• Chi-squared tests (with the plotchisqtest function)
• F tests (with the plotftest function)
• t tests (with the plotttest function)
• z tests (with the plotztest function)

They all work quite the same (with minor differences, see the vignette for more info), with very few required arguments:

• The first required argument is the value of the test statistic z, t, F and Chi-squared
• The other required arguments are the degrees of freedom (except for z of course)

See the vignette for examples and options.

Disclaimer

This package is neither for or against NHST. It’s meant to help explain the process, should you want to explain it. A lot of students (and scholars) have no choice but to read articles with (p) values, so they might as well have a better understanding of what it is and what it’s not anyway, right?