Author: sullystats

Decreasing Body Temperatures

Posted sullystatsLeave a commentPosted in Data Set, Research Article, Statistics Articles

Researchers at Stanford University used data from the Union Army Veterans of the Civil War (1860-1940), the National Health and Nutrition Examination Survey (1971-1975), and the Stanford Translational Research Integrated Database Environment (2007-2017) to determine that the mean body temperature in men and women has decreased by 0.03 degrees Celsius per birth decade.  The reduction in body temperature is a proxy for metabolic rate and this may help to explain the changes in the health of humans and the increase in life expectancy. In 1851, Carl Reinhold August Wunderlich measured the body temperature of 25,000 humans and found that normal body temperature was 98.6 degrees Fahrenheit (or 37 degrees Celsius).  […]

Frames in Polling

Posted sullystatsLeave a commentPosted in Statistics Articles

Random-digit-dialing (RDD) is a popular method for selecting people to be in polls.  So, the population from which a sample is drawn is anyone with a telephone (because RDD dials both listed and unlisted numbers).  A problem with RDD is that of bias as a result of nonresponse.A study by Pew Research compared polling results using random-digit-dialing to the use of registered voter files.  In this study, it was found that in 56 of 65 survey questions, the two polling methods resulted in estimates that were statistically insignificant.Have your students read the article and discuss issues such as frames, nonresponse bias, under-representation, and the overall challenges in finding a sample […]

StatCrunch Featured Data Sets

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In August, 2018, Pearson posted a wide variety of featured data sets that you can use to illustrate a variety of statistical concepts in your class. Each data set on this site has a thorough description of the data and provides a source along with descriptions of each variable. I would like to focus on the “California Home Prices, 2009” data set. This particular data set is interesting because it represents a variety of variables on homes sold in San Luis Obispo county during the financial crisis that started in August, 2008 (including sale type such as regular, foreclosure, or short sale).  Many of our students would have been between […]

Learning Cataltyics

Posted sullystatsLeave a commentPosted in Classroom Strategy

George Woodbury (@georgewoodbury) and I have written a Learning Catalytics course to accompany Interactive Statistics 2/e.  I started classes this week and immediately started using the program in my flipped class.  The level of engagement from my students is enormous and peer-to-peer instruction is taking place.  This has increased the level of understanding of my students and created a dynamic classroom.   I asked my students whether they prefer lecture or Learning Catalytics and they all replied “Learning Catalytics”! If you would like a copy of our course, please email me (sullystats@gmail.com) or George (cosmath21@yahoo.com).

Reproducibility of Research

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The article below discusses how much of the scientific research that folks in the media, the general population, and other “stake-holders” is flawed due to the fact that the results cannot be reproduced.  This is a great illustration of ethics in statistical research.  This could be used to formulate a classroom discussion about the ability to replicate research. How Bad Is the Government’s Science_ – WSJ

Beware the Lurking Variable

Posted sullystatsLeave a commentPosted in Data Set, Statistics Articles

I just completed the discussion on correlation and regression with my Introductory Statistics students. One of the recommendations within the new GAISE outline is to introduce students to multivariate analysis.  A classic application of this practice is the SAT score versus teacher salary data. This data may be found by joining a group I created in StatCrunch titled “SullyStats”. To join the group, go to www.statcrunch.com (if you don’t have a StatCrunch account, ask you Pearson representative for an account).  Under Explore, select Groups. Type SullyStats into the search box and join the group.  The data set is titled “SAT versus Teacher Salaries“ Use the data to illustrate the danger […]

The General’s Dilemma

Posted sullystatsLeave a commentPosted in Classroom Strategy

Today I am going to do “The General’s Dilemma” activity in my Intro Stats class.  I am teaching completely randomized designs, so this is a great opportunity to illustrate the methodology behind this experimental design with this activity.  This data will be used to introduce the inferential methods of comparing two independent proportions using randomization methods.  Feel free to use this in your classes.   Activity – The General’s Dilemma    The following two questions are called the first and second versions of the General’s Dilemma.  The questions were written by psychologists Daniel Kahneman and Amos Tversky.   Version I:  Threatened by a superior enemy force, the general faces a dilemma.  […]