Friday, October 30, 2015

r/faux_pseudo's "Distribution of particles by size from a Cracker Jack box

I love my fellow Reddit data geeks over at r/dataisbeautiful. Redditor faux_pseudo created a frequency chart of the deliciousness found in a box of Cracker Jacks.


I think it would be funny to ask students to discuss why this graph is misleading (since the units are of different size and the pop corn is divided into three columns). You could also discuss why a relative frequency chart might provide a better description. Finally, you could also replicate this in class with Cracker Jacks (one box is an insufficient n-size, after all) or try it using individual servings of Trail Mix or Chex Mix or order to recreate this with a smaller, more manageable sample size.

Also, as always, Reddit delivers in the Comments section:


Monday, October 26, 2015

Orlin's "What does probability mean in your profession?"

Math with Bad Drawings is a very accurately entitled blog. Math teacher Ben Orlin illustrates math principles, which means that he occasionally illustrates statistical principles. He dedicated one blog posting to probability, and what probability means in different contexts.

He starts out with a fairly standard and reasonable interpretation of p


Then he has some fun. The example below illustrates the gap that can exist between reality and reporting.


And then how philosophers handle probability (with high-p statements being "true").


And in honor of the current Star Wars frenzy:


And finally...one of Orlin's Twitter followers, JP de Ruiter, came up with this gem about p-values:




Monday, October 19, 2015

Barry-Jester's "What A Bar Graph Can Tell Us About The Legionnaires’ Outbreak In New York" + CDC learning module

Statistics afficionados over at fivethiryeight applied statistics (specifically, tools used by epidemiologists) to the Summer of 2015 outbreak of Legionnaires' Disease in New York. This story can be specifically used in class as a way of discussing how simple bar graphs can be modified as to display important information about the spread of disease.


This news story also includes a link to a learning module from the CDC. It takes the user through he process of creating an Epi curve. Slides 1-8 describe the creation of the curve, and slides 9-14 ask questions and provide interactive feedback that reinforce the lesson about creating Epi curves.


Graphs are useful for conveying data, but even one of our out staples, the bar graph, can be specialized as the share information about the way that disease spread.

1) Demonstrates statistics being used in a field that isn't explicitly statisticy.
2) A little course online via the CDC for your students to learn to make epi curves.

Monday, October 12, 2015

U.S. Holocaust Mueseum's "Deadly medicine, creating the master race" traveling exhibit

Alright. This teaching idea is pretty involved. It is bigger than any one instructor and requires interdepartmental effort as well as support from The Powers that Be at your university.

The U.S. Holocaust Museum hosts a number of traveling exhibits. One in particular, "Deadly Medicine: Creating the Master Race", provides a great opportunity for the discussions of research ethics, the protection and treatment of human research subjects, and how science can be used to justify really horrible things.


I am extraordinarily fortunate that Gannon University's Department of History (with assistance from our Honors program as well as College of the Humanities, Education, and Social Sciences) has worked hard to get this exhibit to our institution during the Fall 2015 semester. It is housed in our library through the end of October.

How I used it in my class: My Honors Psychological Statistics class visited the exhibit prior to a discussion day about research ethics. In preparation of the discussion day, they also read the US Department of Health and Human Service's list of individuals who fall under protected class status, listened to a news story about recent revelations regarding WWII-era research on mustard gas using American soldiers who belonged to minority groups, and read a description of the Hoffman Report and the APAs cooperation in development of interrogation techniques used during Operation Iraqi Freedom.

The discussion prompts my students generated were largely about war time research ethics, and the consensus was that even during war time, research ethics still need to be enforced.

Highlights from the discussion in my class:

-Students discussed how a understanding of the social circumstances surrounding these unethical research decisions was critical for understanding how such choices could be made. For instance, prejudice in America was far more acceptable during WWII than today. Post-9/11 America was not very tolerant of anyone who didn't fully support the president. How much freedom did German doctors have to deviate from the ultimate solution?

-My students also got into an interesting discussion on whether or not it would be ethical to analyze the data that came out of Nazi research. Some students argued that if the data could be used to gain insight into the conditions so loathed by the Nazis. As such, any research findings could be a glimmer of good coming out of an awful situation. Other students returned to what they have learned about research ethics and argued that since informed consent was not gained and research participation was not voluntary, such data was completely tainted. Another student brought up the fact that they have a sibling that would have probably been labeled "undesirable" by the Nazi regime and that they would want any data related to their sibling destroyed because they would feel that such data would put their sibling on display.

-Discussion of how the Department of Health and Human Services could be strengthened to avoid future ethical problems. Suggestions included a clearer definition of minimum risk and examples of minimum risk across a broad array of situations as well as better power for fining for unethical research studies.

-A broad discussion as to whether or not the argument that research must be conducted "For the Greater Good" is ever a sound argument or a reason for research ethics to be ignored.

Frankly, it was an awesome discussion.

How this exhibit can supplement a research methods class:

1) The main thrust of this display really is eugenics, in particular, the elimination of people with any perceived or real mental disorders, ranging from epilepsy to low IQs to behavioral problems.

I think this makes this exhibit of particular interest to psychology majors, as these are the very groups that many of our students wish to serve. It is sickening contrast to see how many groups that have currently have protected class status (for research purposes) were the exact groups targeted and exterminated by the Nazis.

2) The use of science to protect unconscionable choices. The display begins by describing how the eugenic movement took Darwin's original work and turned it into an argument for a) the creation of a master race as well as b) the dehumanizing of anyone who didn't fit the description of the master race. All of this was backed up by science and by renowned scientists from this period. This is a good way of introducing why ethical review boards are necessary but also how they can be limited by certain regimes that have their own agendas and end goals. It also might be a good exercise to show students current standards for IRB approval and contrast this with the horrible things that were done during the Holocaust.

3) This also serves as an important tool for social psychology. It conveys how laws and rules were enacted over time that eventually made it possible for large groups of people to dehumanize and murder a perceived sub-human class of people. This display also describes the persuasive tools used by the Nazis in order to justify this behavior (better use of resources by not providing for members of society unable to care for themselves).

Practical concerns for getting this exhibit to your university:

If you look at the logistics for the exhibit, it is pretty involved to bring this to your campus (application material here), both financially as well as the physical hosting and securing of the exhibit. The exhibit consists of a bunch of portable walls that tell the story of the use of eugenics and the study of eugenics by the Nazis. It contains a few flat-screen TVs with documentaries and witness testimony.

I think that it might be a nice opportunity to bring together faculty in biology, history, political science, psychology, philosophy, etc. as well as student groups (centers for social concern, Hillel, history clubs, ethics/philosophy clubs, Psi Chi) that may be interested in assisting with hosting duties/fees. Student involvement is especially important as the exhibit requires volunteer docents to curate the exhibit.

Monday, October 5, 2015

How NOT to interpret confidence intervals/margins of error: Feel the Bern edition

This headline is a good example of a) journalists misrepresenting statistics as well as b) confidence intervals/margin of error more broadly. See the headline below:



In actuality, Bernie didn't exactly take the lead over Hillary Clinton. Instead, a Quinnipiac poll showed that 41% of likely Democratic primary voters in Iowa indicated that they would vote for Sanders, while 40% reported that they would vote for Clinton.

If you go to the original Quinnipiac poll, you can read that the actual data has a margin of error of +/- 3.4%, which means that the candidates are running neck and neck. Which, I think, would have still been a compelling headline. 

I used this as an example just last week to explain applied confidence intervals. I also used this as a round-about way of explaining how confidence intervals are now being used as an alternative/compliment to p-values.