Clearly Critically Thinking?

I have been making a real effort to assess my student’s ability to think critically this semester in a more formal way and posted the following questions for them to answre attached to the graph below.  Are the questions clear?  I will admit that the wording could have been better (next time I will ask “does the graph *directly* support”, versus “is this  support”).

Please vote below…. feel free to leave any comments.  Thanks for helping  me become a better teacher 🙂

6.  The graph below shows the total corn acres planted  and acres harvested.  You are working as a commodities analyst for a brokerage firm and your job is to advise your clients on whether they should invest in corn in any given year.  You often go through old data to make your predictions.  While showing this graph to your boss, he remembers that there was a LOT of rain in 2007.  He points to the increase in the 2007 corn harvest and says “It was because that year was very wet”.

Does the graph support his statement? (yes/no/I don’t know)

7. How might you go about determining  if the 2007 corn harvest was in fact higher?


I might as well ask for your answers to the question:


About SubOptimist

I am an Associate Professor in the Science Department at Georgia Perimeter College, Clarkston. I teach introductory biology courses at both the majors and non-majors level in addition to microbiology. Previous to that I spent 7 years as a postdoctoral researcher on different viruses. While I don't miss being on the "grant treadmill", I think better when I write and miss writing up data for papers and grants; this blog helps me with that a little. And sometimes my kids' insanely funny and cute antics need to be shared with the world. Any view expressed in this blog is that of me personally and not Georgia Perimeter College or the GPC Clarkston Science Department.
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11 Responses to Clearly Critically Thinking?

  1. Blaise Pascal says:

    Aside from it being a bad graph (the y axis doesn’t go to 0), question 7 is unclear because I can’t tell if by “corn harvest” you mean the amount of corn harvested (eyeballed at 86 million acres) or the percentage of planted corn actually harvested (roughly 92%).

    • SubOptimist says:

      All good points. The bad graph is intentional as I tend to ask more questions later in the semester about the same graph, plus ask the same questions again to see if they can pick this apart better. Thanks!

  2. Michael Fisher says:

    Q7. You write this:- “…was in fact higher?” & I think “Higher than what?” “Higher than when?”

  3. RussAbbott says:

    Presumably the amount of corn planted in 2007 was not affected by the rain. Yet it spiked too. Also the graph does not show rainfall in any year. Can we really rely on the boss’s memory?

    Is your point to get students to make these sorts of observations?

    • SubOptimist says:

      This particular graph question is for a non-majors intro bio class called Plants & People. The crop data is directly relevant to the content, but an important objective here is to increase students’ ability to critically evaluate information generically. I would be very happy if my students could say that the acres planted in 2007 was higher and that is the most likely explanation for the increased harvest.

  4. Michael Fisher says:

    Me again ~ I think this would be a more useful excercise if you posted the entire set of questions & any other material the students would be referencing with it.

    Q7:- “How might you go about determining if the 2007 corn harvest was in fact higher?”
    I don’t have the entire paper to look at so I’m unsure what’s being asked for here ~ it’s a woolly question…

    It might merely be asking me to observe that the graph is at a local maximum in 2007 or
    It might be asking me to test the truth of the data by looking at the sources from which the graph was built or
    is it a deeper question about how the USDA collects & analyses data?

    There’s a few other ways that this question could be understood ~ good for a class discussion, but not a test I feel

    • SubOptimist says:

      If I put these on a test, yes I would give more information, but I give these as online weekend “I don’t know” quizzes with multiple choice questions from AAAS project 2061’s assessment site designed to test mis-perceptions about the material to be covered in the next week (incredibly helpful to know those before putting my lectures together). I have two goals with this particular type of question: (1) can students identify whether a statement is supported by the data in a graph and (2) can they come up with the *type* of information they would need next. As you pointed out, I bungled the second question (7, and thank you, I will modify before I put it up this weekend). The more interesting thing to me is that last semester when I put this up ~80% of the students selected “Yes, this graph supports the boss’s statement” when clearly the reason the harvest was bigger in 2007 was because they planted more acres. This is why I asked Larry for your all’s help; 92% of you picked “No”. That tells me that, while there is a problem with #7, it is pretty clear that the boss’s statement isn’t supported. Well see how they do this semester. Remember, these are not future scientists; typically they are headed into early childhood education, business, sports management etc etc. They are however, voters, and wouldn’t it be nice if voters were more skeptical of their information?

  5. jlinzel says:

    Generally speaking I find consistency in the use of vocabulary to greatly help students to understand what is expected of them. The International Baccalaureate [IB] program uses specific ‘command terms’ to make this clear. I would suggest you formulate question generation using specific terms. The IB list is a good place to start. See here:


    • SubOptimist says:

      I am all for consistency too and include explicit verbs on exams…however, at some point students (especially my Micro students, most are heading into allied health fields) have to have some practice thinking critically about what an ambiguous statement might mean. Thanks for the link…reminds me of Bloom’s Taxonomy.

  6. Cecilia says:

    This is very useful. Thanks. It seems more important than ever to have students (and the rest of the population) evaluating information.

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