Resource Library

This collection of datasets from Princeton University each come with detailed descriptions of the data's history, how it was collected, and the data quality. Scroll down to "OPR Data Catalog Search" and either type your search terms into the search box or click "complete listings" to browse the archive. Data is available in text format.

This applet allows users to draw a curve on a graph, and then displays the polynomial fit of the curve.

This table shows the critical values values of the Wilcoxon-Mann-Whitney statistics (Us) for various sample sizes (N1 and N2) and p-values (p).

This page provides a table of Chi-square distribution probabilities with degress of freedom 1-45.

This page helps readers know which statistcal tests are appropriate for the different types of data. Two charts display the information. A discussion of study design and sample size, as well as exercise questions with solutions are also provided.

This applet demonstrates the Normal approximation to the Poisson Distribution. Users can set the rate, lambda (‘é), and the number of trials, n, and observe how the shape of the distribution changes. The Poisson distribution is shown in blue, and the Normal distribution is shown in red.

This applet demonstrates the Binomial distribution by simulating Galton's Board, dropping balls through a triangular array of nails. When a ball hits a nail, it has a 50 percent chance of falling to the left or the right. Because Galton's Board consists of a series of experiments, the piles under the board are the sum of n random variables, where n is the number of rows of nails on the board.

This page provides distribution calculators for the binomial, normal, Student's T, Chi-square, and Fisher's F distributions. Users set the parameters and enter either the probability or the test statistic and the calculators return the missing value.

This applet allows users to calculate probabilities from a normal distribution. First, set the mean and standard deviation and click "Scale to Fit". Check one of the boxes next to the inequality signs and enter a value for x; the applet will calculate the z-score and cumulative probability (shown in dark blue for top value and pink for the bottom). By clicking both boxes, users can see the probability between two values (in pink) or outside two values (in blue). Click the inequality sign to change the direction of the cumulative probability.

This applet shows a scatterplot of height versus foot length. Users can add or delete points and then guess the regression line by clicking "Your Line" and moving the blue regression line. By clicking "Regression Line" users can see the actual regression line. The applet also shows the correlation and R-square for the data as well as the residuals and squared residuals for the guessed regression line and the actual regression line.