Can Your Students Interpret Numbers?

A popular saying in business is that “you can’t manage what you can’t measure.” While more businesses these days are relying on intuition and core values as well, it’s true that businesses have to have reliable numbers to be able to stay in business.

This makes it a good idea to give our students at least one assignment in which they need to present and interpret numerical data. I’ve been surprise lately, though, by how poorly my business writing students do this. Perhaps I’m getting a bit of a false read because most of the students in our Writing for Business classes are marketing, IT, and management majors (the students in the more numbers-based majors aren’t required to take this course). If my sample is skewed, I hope you’ll still find the following tips useful.

But first, here’s the situation that prompted me to write this post. The class had been assigned a report-writing task that involved interpreting data from a customer-satisfaction survey for a health clinic. One of the questions on the survey asked the respondents to rate the accuracy the bills they received from the billing office. The answers are shown in this graph:

UN 11.6 billing graph

To my consternation, all but about three of the students interpreted these results as positive! They looked at the columns, saw that the biggest ones were to the left, and thus deduced that the results were pretty good. So we had a discussion about context. Sixty people said their bills were never right? And another 140 said almost never? And another 319 said sometimes? I asked the class how many times they’d need to get an erroneous bill before seriously considering changing healthcare providers. Or how many phone calls to the billing office were probably being generated by this problem. Then they began to get it.

I see what happened as part of a larger issue: Our students are hesitant to think. They’re terrified of making mistakes, and they don’t realize that, to do well on their jobs, they have to problem solve, use their judgment, and put their ideas out there. This is especially the case when they’re asked to interpret information.

For the benefit of future classes, I drew up this list of tips for interpreting and commenting on numbers:

  • Consider the context. Findings that are positive in some situations could be alarmingly bad in others. Figure out what the numbers mean in terms of the problem you’re investigating.
  • Calculate percentages. Often it’s easier for readers to wrap their minds around percentages rather than raw numbers. So, instead of saying “245 strongly agreed” (out of 400), say “61.2% (245) strongly agreed.” (Formula: Divide the number of responses by the total number of participants.)
  • Combine categories of responses when that will be helpful. For example, if you’ve asked respondents to choose an answer on a five-point scale, with the two positive answers at one end of the scale and the negative ones at the other end, it may be more helpful to compare the total number of positive responses to the total number of negative ones than to call attention to just the most positive and most negative answers.
  • Use “majority” correctly. It means “more than half.” It doesn’t mean “those who chose the most popular response” (unless those who voted for the most popular response account for more than half of the respondents). Better yet, try to use more specific wording, such as “just over half” or “the large majority.”
  • Use “average” accurately. “Average” means the median response. (Formula: Add all the responses or ratings and then divide them by the total number.) You cannot say “the average response was ‘sometimes'” when what you really mean is that it was the most common response (the mode).
  • Use the word “most” with care. “Most” doesn’t really have a uniform meaning, but it needs to refer to quite a high percentage of the responses. You would not be justified in saying that “most” respondents chose an answer if only 61% of the respondents chose it. If 85% or more chose it, your use of this word would probably be acceptable.

I realize that this isn’t a very ambitious list. But I hope its overall effect will be to make my students more thoughtful and accurate when reporting numerical data, and I hope it will be of some use to your students as well. If you have tips to add to this list, or have a different way altogether of helping students interpret numbers, please share them.


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