Giving a general feedback, 'you are good, you are doing great job, keep it up, you are indispensable'.., will have no holistic, desired impact. It could actually have a negative effect. The child/team-member may feel there is no need to try harder as he is already 'great'!
But when the feedback is on specifics, 'the particular act' makes you great/indispensable, it works wonders. The recipient knows clearly what particular act makes him great. That sticks and is a motivator.
So the next time we give feedback, let us make it holistic and ensure it serves purpose... ENCHANTS the recipient!
Employee Motivation | How to Really Praise Employees | Inc.com