instructions vs feedback

how can these kids get through a complicated video game but can't follow the instructions on a test?  the answer is rich and meaningful feedback.  instructions don't give feedback.

I wrote about rich feedback in video games as learning environments here: earth defense force

But what about the feedback we teachers aren't even aware we are giving?  Clever Hans effect

I wonder if sometimes when a teacher notices "they are fine in class, but can't do it on the test!" they are actually seeing a student responding to unconscious feedback in class, but lacking feedback on the test.   Then again, if a student can give the appearance of understanding a topic in class by responding to unconscious feedback from a teacher, maybe I'm measuring understanding the wrong way.