There have been more than 110 goal setting experiments conducted in the laboratory and in organizations in just the last twelve years. Ninety percent of these studies obtained positive results for goal setting. This makes goal setting one of the most dependable and robust techniques in all the motivational literature. … A recent study of high and low productivity … found that goal setting and deadlines were the single most frequently mentioned causes of … high productivity. [page 6]
by Edwin A. Locke and Gary P. Latham
See also Managing Yourself with Specific Measurable Results, on this blog.