For the theory-practice iteration to work, the scientist must be, as it were, mentally ambidextrous; fascinated equally on the one hand by possible meanings, theories, and tentative models to be induced from data and the practical reality of the real world, and on the other with the factual implications deducible from tentative theories, models and hypotheses.

Statisticians, like artists, have the bad habit of falling in love with their models.

One important idea is that science is a means whereby learning is achieved, not by mere theoretical speculation on the one hand, nor by the undirected accumulation of practical facts on the other, but rather by a motivated iteration between theory and practice.

The only way to know how a complex system will behave-after you modify it-is to modify it and see how it behaves.

Management must provide employees with tools that will enable them to do their jobs better, and with encouragement to use these tools. In particular, they must collect data.

The benefits provided by worker participation are twofold. Quality is improved because of the finding and fixing of a very large number of problems, but also, and perhaps equally important, moral is improved.

The old-fashioned idea of a good manager is one who is supposed to know all the answers, can solve every problem himself, and can give appropriate orders to his subordinates to carry out his plans... A good modern manager is like a good coach who leads and encourages his team in never-ending quality improvement.