Since I have not been very productive here lately I can at least link to others who are. My colleague Jeff Bardzell has written a great post on his class blog on the distinctions between "opinion" and "judgment". I really like this post.
The notion of judgment is crucial to anyone who tries to understand design. What I am seeing in interaction design is a growing interest in the activity and meaning of "criticism". Hopefully this will also lead to a deeper appreciation and examination of "judgment".
I truly believe that an intellectual and reflective understanding of the two notions criticism and judgment is at the very core of being a good design thinker and design practitioner.