Manual workers are concerned with efficiency, that is, the ability to do things right rather than to get the right things done.
The manual worker is judged by the quantity and quality of an output. He follows set guidelines on how to get his work done.
A knowledge worker uses his knowledge, and by definition his job involves the tasks of planning, acquiring, searching, analyzing, organizing, storing, programming, distributing, marketing, or otherwise contributing to the transformation and commerce of information and those who work at using the knowledge so produced.
Knowledge workers cannot be supervised closely and so they have to be individuals who are self-driven to perform and contibute.
A knowledge worker produces knowledge and his motivation depends on his being effective, and being able to achieve.
Knowledge work is defined by its results, not just by quantity or costs.