Diagnostic Questions

Having heard about the Diagnostic Questions website from Mr Bartons Podcasts, when it came up again at the Cambridge Assessment Questioning Questions conference I thought I'd have a look.

I have always been rather against multiple choice questions for summative assessment. They are often badly written, it might be easy to guess an answer if the alternate answers are clearly implausible. If there are few enough answers then you might be able to pick the correct answer by chance and they don't reflect students thinking or process. However, I can see that there is perhaps a place for them in formative assessment.

The idea behind Diagnostic Questions are that they are carefully written multiple choice questions such that each wrong answer shows a different possible misconception. Also, if you use the website, students are allowed to write in their reasoning so you can see what led them to choose that answer.

Here is an example of a question from the website about fractions. I think it is quite a good question as sometimes when students are completing these types of questions they look at patterns in the chain and each of these examples has a pattern, though clearly a basic understanding of equivalent fractions would allow a student to pick out the correct answer.

As part of the insights you can see the percentage who get the answer right as well as some of the reasons given:

There are a number of students who clearly don't understand what an equivalent fraction is, though nice to see one suggesting that he had thought about a fraction wall! Other types of questions including some kind of fill in the blanks, might not have revealed this much about the thinking.

Here is another example, though you will note that the triangle here is actually impossible:

You can see what reasons students gave for a particular answer. Here are some of the reasons given for students choosing answer D which I think is quite revealing:

We can even se that one student got the a different answer but managed to click the wrong button!

I can see that some of these questions will highlight if some of our students have very particular misconceptions, however I worry that they are being touted as a panacea. I understand the purpose of using one or two carefully written questions during a lesson as a hinge point question however I cannot see the purpose of being able to set the questions as a quiz, or homework. I really think that it is unwise to ask these kinds of questions where there is no immediate follow up to rectify the misconception.

There are also quite a lot of questions on the site that I don't think are particularly well thought out, it would be possible to figure out the answer even if you didn't really understand as none of the other answers are plausible. For example I can't figure out what I might deduce from any of the wrong answers here:

And I'm not even sure what the correct answer is meant to be here:

On reflection I think that having a one or two diagnostic questions in a lesson could help teachers pick out specific misconceptions. Preparing some of these questions collaboratively within a department could definitely support teachers in their planning, though, as always, the most important factor in the outcomes of using these will be what the teacher does to address the misconceptions revealed by the answers.