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

Do I need to constrain the number of groupings as 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.