If you look at this chart, you could be forgiven for thinking where you shop makes you fat. Well, not forgiven, exactly — but look at these huge differences! Less than 5% of Whole Foods shoppers are obese, whereas almost 40% of Albertson’s customers are. So is it something based on what they sell? Nope. [...]
This section deals with the following elements of the COMPARABLE framework: C: Were appropriate comparison groups chosen? Was like compared to like? A1: Which factors were accounted for/controlled for (population, inflation, income) and which were not? There are many rules that apply to making fair comparisons, but there is one rule that leads, in one [...]
This section deals primarily with the following elements of the COMPARABLE framework: E: What is the story of the edges? What is the story of the center? How are they different and what does that mean? THE STORY OF THE CENTER We’ve been looking at various comparisons, in many cases using what statisticians call measures [...]
The following questions can be answered in one to two sentences. While a variety of answers might make sense, there are right and wrong answers here. Think carefully about your answers. Write down your answers and bring them to class. We will review your answers either in class or in a net-mediated peer instruction activity. [...]
This section deals primarily with the following elements of the COMPARABLE framework: L: Would the comparison benefit from a longitudinal/cross-sectional analysis? B: Were base rates considered? Were relative and absolute increases considered? P: Were the pictorial/graphical representations fair and unbiased? Did they help illustrate the data or were they eye-candy? Note to instructors: We are [...]
Questions: 1. Rick Santorum, a candidate for the 2012 Republican nomination, claimed that “62 percent of kids who go into college with a faith commitment leave without it.” [Source: http://bit.ly/A77XED] What is being explicitly compared here? Is it a longitudinal or cross-sectional comparison? If 62 percent is the “part”, what is the “whole”? 2. Of [...]
One of the most common comparison controls we use is controlling for population, both when looking at something societal (percentage of people out of work) and at experimental results (percentage of people experiencing a positive outcome). Percentages and Natural Frequencies Take for example this list of the top 15 countries in terms of number of [...]
This is an amazing chart — sad in one way, but uplifting in another, because it shows how stats-informed public policy can make a difference. The chart represents the incidence of SIDS (“crib death”) in Norway plotted out against the rise and fall of parents that put their children to sleep on their stomach. (Which [...]
As we say in the COMPARABLE checklist, the story is often somewhere in the edges. Take this chart of the proportion of a food dollar which goes to the farmer vs. post-farm activities. At first it seems to show declining farm revenue as the the market bill (which includes everything from transportation to preparation) climbs: [...]
The following is a chart of the Mac OS “Flashback” virus infections over a series of days in 2012. The title of the article is “Flashback waning, but still infecting about 140,000 Macs” 1. Is this a longitudinal comparison? 2. What are the comparison groups? 3. Is this a measure of prevalence or incidence? 4. [...]
Read the following comparison: Consumers now owe more on their student loans than their credit cards. Americans owe some $826.5 billion in revolving credit, according to June 2010 figures from the Federal Reserve. (Most of revolving credit is credit-card debt.) Student loans outstanding today — both federal and private — total some $829.785 billion, according to Mark [...]
We are interested in how music purchasing behavior has shifted over the recent past. What are the strengths and weaknesses of each graph in helping us understand that? Make sure to specify what each graph controls for. From Jailbreaking the Degree: From Evolver.fm:
Via http://dailyinfographic.com/ : Questions: 1. “For every 100 single women in their 20s, there are 120 single men” — If this is true, what else might be true? Explain some ways this pattern could occur. Make sure to double check your hypothesis by running a small mental experiment. 2. Come up with an more outlandish theory for [...]
Via http://dailyinfographic.com/ Questions: 1. On average, how many drowning deaths were there in bathtubs, pools, and hot tubs in August? 2. The graphic states that 71% of deaths occurred in May, June, July, and August. If deaths were equally distributed throughout the year, what amount of deaths would we expect in these months instead? 3. Compute [...]
From http://dailyinfographic.com: Questions: “CTR” is “Click-through rate”, and it represents the percentage of people that see a given ad that actually click on it. 1. Assume the figure they cite is correct. 100,000 people see a Facebook ad. How many click the ad? 2. Assume the figure they cite is correct. 100,000 people see a [...]
From http://dailyinfographic.com: 1. Look at the list of top states. What is not accounted for that should be? 2. There were 1.4 million DUI arrests in 2010. There were 310 million people in the U.S. in 2010. 1.4 / 310 = .0045, or about 4.5 out of 1,000. Does this mean 4.5 out of 1,000 [...]
Via dailyinfographic.com Questions: 1. How many employees do you have to have under to be called a “small business”? 2. What qualifies as a small business? If I sell things ocassionally on Amazon.com or Etsy, is that a small business? If am the CEO of Walmart, but create a small one person company to invest [...]
Via dailyinfographic.com: 1. Where is the information from? Can you find any of the source statistics? 2. Two children are born into a family two years apart. All other things being equal who is more likely to be an entrepreneur — the first-born or second-born child? [Note: as with all questions, you can say we [...]
What are the sources of this information? Who put the infographic together? In what way are the comparisons inadequate? Look at the scale of the graphic. What do the lengths mean?
From http://www.mindbodygreen.com/0-4543/14-MindBlowing-Facts-About-Sugar-Infographic.html First, a comment — note how nicely their sources are laid out. You don’t know what goes to what, but at least you have a starting point. Now, questions: 1. Source: Who is OnlineSchools? What’s their stake in this issue? Did they collect the data, or did someone else? 2. Look at comparison [...]
Did overbuilding houses lead to the recession? Matthew Yglesias shows this graph to demonstrate that overbuilding wasn’t the problem: He explains: On the general subject of recession myths, here’s another statistical look at the myth that the speculative boom in land prices led to some kind of crazy amount of overinvestment in houses. What we [...]
A chart of the growth of Draw Something, a game played on smartphones and tablets: Question: Is this growth linear or non-linear? Defend your answer.
1. Name three things this graph tells you. Deal with the significance of the standard deviation if possible. 2. Name three things it doesn’t. 3. Apply at least one aspect of the COMPARABLE framework to it explicitly.
From http://www.dartmouth.edu/~benv/files/poll%20responses%20by%20party%20ID.pdf YouGov interviewed 1056 respondents who were then matched down to a sample of 1000 to produce the final dataset. The respondents were matched on gender, age, race, education, party identification, ideology, and political interest. YouGov then weighted the matched set of survey respondents to known marginal for the general population of the [...]