This test checks whether an observed distribution differs from an expected distribution. It computes the chi-square statistic, degrees of freedom (DoF), and p-value. Users input a table with row and column labels, observed frequencies on the first row, and expected frequencies on the second row. The null hypothesis is that the observed values have the expected frequency distribution.
This site links to social science data archives all over Europe. By clicking "The Cataloge" users can search for datasets from any country's data archive or go directly to a data archive website by clicking the name of the country. By clicking "The Map" users can see a map of the locations of European data archives and click the country whose archive they would like to see. Some archives require registration to access the datasets.
This page provides a z-table with alpha levels from .00 to .09.
This page provides a t-table with degrees of freedom 1-30, 60, 120, and infinity and seven levels of alpha from .1 to .0005.
This page introduces contigency tables with an example on fruit trees and fire blight. Two calculators are provided that allow users to enter their own contigency table and test for treatment effects. The first calculator performs Fisher's Exact Test on a 2x2 tables. The second performs a chi-square test on up to a 9x9 table.
This page introduces the Kolmogorov-Smirnov test, gives background and procedures for the test, and provides a calculation page which allows users to enter their own data and perform the test.
BrightStat is a free online application for statistical analyses. Besides many non-parametric tests, BrightStat offers multiple linear regression, logistic regression, ANOVA and repeated measurements ANOVA as well as Kaplan Meier Survival analysis. BrightStat has an easy to use GUI and supports the creation of mostly used scientifc graphs such as line-, bar-, scatter- and box-plots as well as histograms.
Compared to probability calculators, the traditional format of distribution tables has the advantage of showing many values simultaneously and, thus, enables the user to examine and quickly explore ranges of probabilities. This webpage includes a list of distributions and tables, including the standard normal (Z) table, student's t table, chi-square table, and F distribution tables. An animation of the density function and distribution function is shown above each distribution table to demonstrate the effects changing degrees of freedom and significance levels have on the shape of a distribution.
This software makes it easier to use the R language. It includes a code debugger, editing, and visualization tools.
Rseek.org is a search engine for R resources. Type any topic in the search box, and get resources that are R specific. You can further narrow your search to just articles, books, packages, support, or "for beginners."