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Showing posts with the label environment

Flowingdata's Car Costs vs. Emissions story

FlowingData shared some interesting info on how much cars cost version their environmental footprint .  TL;DR: Low emission cars tend to be cheaper in the long run. Hooray for the free market! The data is also available via the New York Times , along with a much more in-depth conversation about the actual cost of high/low emission cars, but it is behind a paywall. The original data, presented in a fun (nerd fun) interactive website , is available here.  How to use it in class: 1) It's a correlation! Each car model is a dot with two related data points: Average cost per month and average carbon dioxide emissions per mile.  2) It's Simpson's Paradox! Note how electric cars (yellow cloud all have similar emissions, but the average cost per month varies. Same for Diesel cars. Overall, you still see the positive correlation in the data, but if you break it down by class of car, the correlation isn't present for every level. 

Data controversies: A primer

I teach many, many statistics classes. In addition to the core topics typically covered in Introductory Statistics, I think covering real-life controversies involving statistics is vital. Usually, these are stories of large organizations that attempted to bias/PR attack/skew/p-hack/cherry-pick data to serve their own purposes.  I believe that these examples serve to show why data literacy is so critical because data is used in so many fields, AND our students must prepare themselves to evaluate data-based claims throughout their lives. I put out a call on Twitter , and my friends there helped me generate a great list of such controversies. I put this list into a spreadsheet with links to primers on each topic. This isn't an in-depth study of any of these topics, but the links should get you going in the right direction if you would like to use them in class. I hope this helps my fellow stats teachers integrate more applied examples into their classes. If you h...

Transforming your data: A historical example

TL:DR: Global water temperature data from <1940 was collected by sailors collecting buckets of water from the ocean and recording the temperature of their bucket water. But some recorded data was rounded (thanks, Air Force!). Then, researchers had to transform their data. ^Go to the 3 minute mark to see the bucket-boat-water-temperature technique in action Here is the original research,  published in Nature . NPR covered the research article . Reporter Rebecca Hersher didn't discuss the entire research paper. Instead, she told the story of how the researchers discovered and corrected for their flawed ocean water temperature data. This story might be a little beyond Intro Stats, but it tells the story of messy, real archival data used to inform global climate change and b) introduces the idea of data transformations. Below, I will highlight some of the teaching items. Systematic bias: The data were all flawed in the same way as they were transcribed without any da...

CNN's The most effective ways to curb climate change might surprise you

CNN created an interactive quiz that will teach your students about a) making personal changes to support the environment, b) rank-order data, and c) nominal data. https://www.cnn.com/interactive/2019/04/specials/climate-change-solutions-quiz/ The website leads users through a quiz. For eight categories of environmental crisis solutions, you are asked to rank solutions by their effectiveness. Here are the instructions: Notice the three nominal categories for each solution: What you can do, What industries can do, What policymakers can do. Below, I've highlighted these data points for each of the "Our home and cities" solutions. There are also many, many examples of ordinal data. For each intervention category, the user is presented with several solutions and they must reorder the solutions from most to least effective. How the page looks when you are presented with solutions to rank order: The website then "grades" your respons...

Free beer (data)!

I am absolutely NOT above pandering to undergraduates. For example, I use beer-related examples to illustrate t-test s,   correlation/regression , curvilinear relationships , and data mining/re-purposing . Here is some more. This data was collected to estimate how much more participants would pay for their beer if their beer was created in an environmentally sustainable manner. The answer? $1.30/six pack more. And 59% of respondents said that they would pay more for sustainable beer. NPR talked about it , as well as ways that breweries are going green. Here is a link to the original research . How to use in class: 1) The original research is shared via an open source journal . So, an opportunity to talk about open source research journals. 2) They data was collected via mTurk, another ancillary topics to discuss with your budding research methodologists. 3) The authors of the original study shared their beer survey data ! Analyze to your heart's content. 4) How c...

Climate Central's The First Frost is Coming Later

So, this checks off a couple of my favorite requisites for a good teaching example: You can personalize it, it is contemporary and applicable, it illustrates a few different sorts of statistics.  Climate Central wrote this article about first frost dates, and how those dates, and an increasing number of frost-free days, create longer growing seasons.  The overall article is about how frosty the US is becoming as the Earth warms. They provide data about the first frost in a number of US cities. It even lists my childhood hometown of Altoona, PA, so I think there is a pretty large selection of cities to choose from. Below, I've included the screen grab for my current home, and the home of Gannon University, Erie, PA. The first frost date is illustrated with a line chart, but the chart also includes the regression line. Data for frosty, chilly Erie, PA The article also presents a chart that shows how frost is related to the length of the growing season in t...

Correlation example using research study about reusable shopping bags/shopping habits

A few weeks ago, I used an NPR story in order to create an ANOVA example for use in class. This week, I'm giving the same treatment to a different research study discussed on NPR and turning it into a correlation example. A recent research study found that individuals who use reusable grocery store bags tend to spend more on both organic food AND junk food. Here is NPR's treatment of the research .  Here is a more detailed account of the research via an interview with one of the study's authors.   Here is the working paper that the PIs have released for even more detail.  The researchers frame their findings (folks who are "good" by using resuable bags and purchasing organic food then feel entitled to indulge in some chips and cookies) via "licensing", but I think this could also be explained by ego depletion (opening up a discussion about that topic). So, I created a little faux data set that replicates the main finding: Folks who use reusable ...