Sorry, you need to enable JavaScript to visit this website.

Variable Validity, Reliability, Bias

  • "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).
    0
    No votes yet
  • "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."
    0
    No votes yet
  • 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.
    0
    No votes yet
  • 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.
    0
    No votes yet
  • 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
    0
    No votes yet
  • 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.
    0
    No votes yet
  • This website provides links to instructions for performing basic statistics such as confidence intervals, hypothesis tests, discrete distributions, linear regression, etc. for TI 83, TI 84, and TI 86 calculators.
    0
    No votes yet
  • This article provides the example of student form orders to demonstrate the unreliability of combining data from two different distributions (or subjects).
    0
    No votes yet
  • This paper presents rules for determining whether an index variable in such a table is part or whole depending on whether the associated margin value is an average, a sum or a 100% sum. Tables with missing margin values -- date-indexed tables, half tables and control tables -- are analyzed. Recommendations are made to improve reader understanding of any table involving rates or percentages.
    0
    No votes yet
  • This is a three day lesson plan. The first day is an introduction to concepts in probability. The second day is an application of probability in the field of genetics. The third day is a time for students to expand their understanding of probability and genetics via short research project. The site includes resources, advice, and notes to the teacher. Probability topics include: law of large numbers, simple and compound events, sample size, sample space, and more.
    0
    No votes yet

Pages