First, let’s define the two methodologies:

Card sorting: research methodology used to better understand how users group concepts by having them sort, categorize and group cards on which are written information describing an interface’s contents.

Tree testing: research methodology used to test a given architecture by having users complete tasks through navigation in a menu structure

Now, let’s move on to 6 simple principles that will help aspiring usability experts better understand those two very useful methodologies. Read more