Understanding large numbers in context, an exercise with socrative

I came across an exercise that aimed to demonstrate that numbers are easier to understand when broken  down and put into context, it’s one of a number of really useful resources for the general public, journalists and teachers from the Royal Statistical Society. The idea is that large numbers associated with important government budgets–you know, a few billion here, a few billion there, pretty soon you’re dealing with large numbers–but such large numbers are difficult to get our heads around, whereas the same number expressed in a more familiar context, e.g. a person’s annual or weekly budget, should be easy to understand.  I wondered whether that exercise would work as an in-class exercise using socrative,–it’s the sort of thing that might be a relevant ice breaker for a critical thinking course that I teach.

A brief aside: Socrative is a free online student response system which “lets teachers engage and assess their students with educational activities on tablets, laptops and smartphones”. The teacher writes some multiple choice or short-response questions for students to answer, normally in-class. I’ve used it in some classes and students seem to appreciate the opportunity to think and reflect on what they’ve been learning; I find it useful in establishing a dialogue which reflects the response from the class as a whole, not just one or two students.

I put the questions from the Royal Stats. Soc. into socrative as multiple choice questions, with no feedback on whether the answer was right or wrong except for the final question, just some linking text to explain what I was asking about. I left it running in “student-paced” mode and asked friends on facebook to try it out over the next few days. Here’s a run through what they saw:

Screenshot from 2015-03-31 14:54:19Screenshot from 2015-03-31 14:55:13Screenshot from 2015-03-31 14:55:52Screenshot from 2015-03-31 14:56:40Screenshot from 2015-03-31 14:58:46Screenshot from 2015-03-31 14:59:21


Socrative lets you download the results as a spreadsheet showing the responses from each person to each question. A useful way to visualise the responses is as a sankey diagram:
sankeymatic_1200x1000 (1)

[I created that diagram with sankeymatic. It was quite painless, though I could have been more intelligent in how I got from the raw responses to the input format required.]

So did it work? What I was hoping to see was the initial answers being all over the place, but converging on the correct answer, that is not so many chosing £10B per annum for Q1 as £30 per person per week for the last question. That’s not really what I’m seeing. But I have some strange friends, a few people commented that they knew the answer for the big per annum number but either could or couldn’t do the arithmetic to get to the weekly figure. Also it’s possible that the question wording was misleading people into thinking about how much would it cost to treat a person for week in an NHS hospital. Finally I have some odd friends who are more interested in educational technology than in answering questions about statistics, who might just have been looking to see how socrative worked. So I’m still interested in trying out this question in class. Certainly socrative worked well for this, and one thing I learnt (somewhat by accident) is that you can leave a quiz running in socrative open for responses for several months.