Proofreading a friend's work, I came across the following phrase:
[teachers and students] work collaboratively to change long held, potentially incorrect and deeply believed views
Now, while I'm sure that in suggesting hyphenation for "long-held" and "deeply-believed" I'd be correct, for a reason I can't quite put my finger on I don't think hyphenating "potentially incorrect" would be appropriate. Am I correct, and if so, what distinguishes this phrase from the others?