Do you assign marks alongside comments for formative assessment? You could be wasting your time.

During my research for my posts on the power of feedback and formative assessment, I came across a series of studies involving Israeli 5th, 6th and 7th graders in the late 80s.

In one study, students were divided into three groups and tested twice:

  • Group 1 got only feedback on their work but no marks; 
  • Group 2 got only marks, without any feedback whatsoever, and
  • Group 3 got both marks and feedback.

Group 1 improved by a solid 30% on average, while Group 2 did not improve at all. This makes sense, as they weren't given any suggestions as to how they would be able to improve. However, I was very surprised to learn that Group 3 performed just like Group 2 and didn't improve at all!

far from producing the best effects of both kinds of feedback, giving marks alongside the comments completely washed out the beneficial effects of the comments.

The use of both marks and comments is probably the most widespread form of feedback used in the Anglophone world, and yet this study (and others like it — see below) show that it is no more effective than marks alone. In other words, if you write
careful diagnostic comments on a student’s work, and then put a score or grade on it, you are wasting your time.
— Dylan Wiliam, 'Keeping learning on track: Formative assessment and the regulation of learning'

If you're interested in finding out more, read Dylan Wiliam's paper. Pages 24 – 28 give a particularly valuable insight into the quality of feedback.


Guido Gautsch I Ed Specialist @ Stile