Variable Validity, Reliability, Bias

• Galaxy Hunter: A Cosmic Photo Safari (JAVA required)

Explore the Hubble Deep Fields from a statistical point of view.  Watch out for the booby traps of bias, the vagueness of variability, and the shiftiness of sample size as we travel on a photo safari through the Hubble Deep Fields (HDFs).

• Logistic Regression & Common Odds Ratios Part II (with Simulations)

This presentation is a part of a series of lessons on the Analysis of Categorical Data. This lecture covers the following: Mantel-Haenszel estimator of common odds ratio, confounding in logistic regression, univariate/multivariate analysis, bias vs. variance, and simulations.

• Penn State STAT 509: Design and Analysis of Clinical Trials

This is a graduate level survey course that stresses the concepts of statistical design and analysis in biomedical research, with special emphasis on clinical trials. Perfect for students and teachers wanting to learn/acquire materials for this topic.

• Quote: Heisenberg on Observing Nature

"We have to remember that what we observe is not nature herself, but nature exposed to our method of questioning." is a quote by German Physicist Werner Heisenberg (1901-1976) that can be used in discussing the validity of measurements. The quote arose in a series of lectures delivered at University of St. Andrews, Scotland in the 1955-1956 academic year and published in Physics and Philosophy: The Revolution in Modern Science (1958).
• Quote: Yule on Measurement

"Failing the possibility of measuring that which you desire, the lust for measurement may, for example, merely result in your measuring something else - and perhaps forgetting the difference - or in your ignoring some things because they cannot be measured." A quote by British statistician George Udny Yule that can be used in discussing the validity of measurements. The quote is contained on the last page of his famous 1921 British Journal of Psychology paper "The essentials of mental measurement." The quote is commonly paraphrased as "In our lust for measurement, we frequently measure that which we can rather than that which we wish to measure... and forget that there is a difference."
• Song: Empty Time with Normal Tables

A song that might be used in pre-service courses for statistics teachers (or professional development workshops) to point out why using technology is preferred to training students to use Normal Probability Tables. The lyrics were composed by Robert Carver of Stonehill College. May be sung to the tune of the "Empty Chairs at Empty Tables" written by Schoenberg and Kretmer for the play Les Miserables. The lyrics won an honorable mention in the CAUSE 2013 A-Mu-sing contest. Musical accompaniment realization and vocals are by Joshua Lintz from University of Texas at El Paso.
• Cartoon: Fishing

A cartoon that might be used in teaching about data quality issues. Cartoon by John Landers (www.landers.co.uk) based on an idea from Dennis Pearl (The Ohio State University). Free to use in the classroom and on course web sites.

• Cartoon: The Measurement Machine

A cartoon to teach about the measurement issues of bias, reliability, and validity. Cartoon by John Landers (www.landers.co.uk) based on an idea from Dennis Pearl (The Ohio State University). Free to use in the classroom and on course web sites.
• Regression Activity

This activity focuses on basic ideas of linear regression. It covers creating scatterplots from data, describing the association between two variables, and correlation as a measure of linear association. After this activity students will have the knowledge to create output that yields R-square, the slope and intercept, as well as their interpretations. This activity also covers some of the basics about residual analysis and the fit of the linear regression model in certain settings. The corresponding data set for this activity, 'BAC data', can be found at the following web address: http://www.causeweb.org/repository/ACT/BAC.txt

• Cohabitation

This module is designed to illustrate the effects of selection bias on the observed relationship between premarital cohabitation and later divorce. It also serves as a review of key methodological concepts introduced in the first part of the course.