Resource Library

A song lyric by Dennis Pearl of The Ohio State University written as a parody of the 1960 tune "Hit the Road Jack" by Percy Mayfield; made popular by Ray Charles in his 1961 recording. What to say in class before song: There are times when the mode may be preferred to the mean - especially if the concept of interest is tied to understanding the most likely situation. You might remember that Ray Charles used to sing a song about this... In a class where Bayesian and Maximum Likelihood methodology has been introduced you might add the following after the first sentence "For example when you assume a uniform non-informative prior for a parameter, then the m.l.e. coincides with the mode of the posterior distribution - and the mean of the posterior distribution may not be a good estimate." Tip for Teaching: The song takes up a bit too much class time for delivering its message. Thus, for in-class use, it is recommended to play only the first verse or three. Musical accompaniment realization and male vocals are by Joshua Lintz, female vocals are by Mariana Sandoval from University of Texas at El Paso.

This applet performs the Student's t test on two sets of data, and reports the average and variance for both sets of data, the t score, degrees of freedom, and one and two tailed P values.

This java applet can be used to determine whether or not the means in two sample populations are significantly different.

This applet demonstrates the concept of power. Users select the hypothesized mean, the alternative mean, the sample size, and the number of samples. The applet shows the hypothesized histogram and the alternative histogram. Users then select either the level of significance and set alpha or the rejection region and set the test statistic. The applet then shows the p-value (in red) and power (in green). User can also determine the direction of the test by clicking the inequality sign.

This page of Statistical Java describes 11 different probability distributions including the Binomial, Poisson, Negative Binomial, Geometric, T, Chi-squared, Gamma, Weibull, Log-Normal, Beta, and F. Each distribution has its own applet in which users can manipulate the parameters to see how the distribution changes. The parameters are described on the main page as well as situations that would use each distribution. The equations of the distributions are not given. To select between the different applets you can click on Statistical Theory, Probability Distributions and then the Main Page. At the bottom of this page you can make your applet selection. This page was formerly located at http://www.stat.vt.edu/~sundar/java/applets/

(Uses JAVA)  Some basic statistical analysis tools that allow the user to input their own data or use the pre-existing data and perform the desired test (e.g ANOVA, Descriptive, t-test, chi-square, correlation and regression).

This applet allows the user to enter data, then returns the values of empirical cumulative distribution function by sorting the data and reporting the height of the curve at each point. It does not show the graph.

This page calculates either sample size or power for a one sample binomial problem. Users choose between a one-sided and two-sided test and specify the null and alternative hypothesized proportions. The calculator also gives the critical value.

This tutorial exposes students to conducting t-tests in SPSS. This html based tutorial provides extensive screen shots and two example data sets. Topics covered in the tutorial include one sample, paired and independent samples t-tests and conducting transformations (such as a difference) of the data.

This page calculates either estimates of sample size or power for differences in proportions. The program allows for unequal sample size allocation between the two groups.