Overconfidence among beginners: is a little learning a dangerous thing?

There does appear to be truth in the oft repeated excerpt from Alexander Pope's poem, ' A little learning is a dangerous thing. Studies done by Cornell university and Michigan University demonstrate clear increase in the speed and decision-making of task assigned to beginners of the tasks. This over-confidence appeared to plateau and then peter-out as more experience was actually gain and deeper thought put into the task at hand.