Some feedback quotes from previous blog entries: From Agile development in the large
Quick feedback should be the first thing you introduce.

From What did you say?
We structure our world so we will not receive feedback that threatens our view.
We don't even wait to ignore feedback, but actively take steps to prevent such feedback from ever happening in the first place.
Don't concentrate on giving feedback; concentrate on being congruent - responding to the other person, to yourself, and to the here-and-now situation.

From The dance of life
All societies depend for the stability on feedback from the people. Depersonalization reduces feedback to a minimum, contributing to instability and lowering the overall level of congruence in the society.

From Understanding the professional programmer
Many programmers… work in environments in which they receive essentially no real feedback embodying the consequences of what they do. Lacking no real feedback, they lack the motivation to attempt changes, and they also lack the information needed to make the correct changes.

From Quality Software Management. Vol 2. First-Order Measurement
Software development is not primarily a manufacturing operation for we (ideally) never develop the same software twice. This uniqueness of product means that Deming's "statistical signal" - though necessary - is not sufficient for feedback control, because there often isn't enough repetition - enough stability - to generate meaningful statistics.

From Quality Software Management. Vol 4. Anticipating Change
In a feedback control system it's only our perception that determines which is controller and which is controllee.

From The systems bible
Just calling it "feedback" doesn't mean that it has actually fed back. To speak precisely: It hasn't fed back until the system changes course. Up until that point it's merely sensory input.

From Talent is overrated

Practicing without feedback is like bowling through a curtain that hangs down to knee level. You can work on technique all you like, but if you can't see the effects, two things will happen: You won't get any better, and you'll stop caring.

From the Principles of product development FLOW
Fast local feedback loops prevent the accumulation of variance.

From the Aesthetics of change
All simple and complex regulation as well as learning involve feedback. Contexts of learning and change are therefore principally concerned with altering or establishing feedback.