Suggested number of groups in open card sorting

Question

I'm going to use OptimalWorkshop for conduct an open card sorting exercises (unmoderated) with about 35 cards. I will recruit about 40 participants.

• Do I need to constrain the number of groupings while introducing the card sorting exercises?
• What is the recommended range?
• Or is it better to leave it as "group the information in the way and number you consider fit?"

For example, I imagine the responses may look very different if we tell a participant that they have to get it down to 2-4 groupings vs. 7-10 groupings.

Answer 1

The idea of an open card sort is that you leave the sorting unrestrained. If you start limiting the number of groups you're influencing that process. If you do want to constrain them by providing categories use closed card sorting or a combination.

As always it depends on your starting point and hypotheses to test. What is the goal for doing this?

If you want to know what groups user will create go for an unrestrained open card sort and simply let it run. The essense of this method is that it gives you a better idea of the users mental model. Thus there's no wrong way to group. In the end it doesn't help if you supply users with restraints that are possibly flawed. It'll only create confusion

If you already have 1 or more categories use a closed or open/closed card sort. For example when the navigational categories are already more or less fixed and you want to know how to group the subcategories. If needed ask them to group any outlying cards in new categories.