I thought I might try to give some vaguely helpful advice for new teachers on the card sorts front. Maths seems to be full of them, especially from the Standards Unit which was the number one cited resource by a long shot at SI 2012.
What I do now is look through the card sort and imagine model keen-bean students (of the ability of the set I’m planning for) trying the card sort. What questions would they have? What categorisations would they quibble over? Where would they disagree? Where’s the cognitive conflict?
For example, in a shape categorisation card sort, whether this is a pentagon or not would be a rich source of debate for my imaginary keen beans:
All too often in a paired card sort activity, they would categorise this without thinking or one student would just overrule the other based on popularity or ego size rather than mathematical debate. The quality discussion which draws out misconceptions happens far less often than the Standards Unit authors would like to think, in my opinion.
Anyway, I generate the list of imagined key discussion points. I put statements or questions associated with (one, or two, or many of) them on my powerpoint.
So I’d put that picture of the pentagon up and write. “This is a pentagon. True or false?” underneath it.
Now we can have a class discussion, or a “think pair share”, or a minute of “everybody writes” specifically focused on that crucial misconception.
Far easier to manage, far easier to focus the children’s thoughts on the key areas, far less time consuming to produce.