Feedback and Control for Everyone

Vertrouwen hebben is goed, in controle zijn is beter! Confidence is good, but to be in control is better! La confianza esta bien, !pero el control es mejor...! La informacion suele ser buena, !la realimentacion es esencial! Information is important but feedback is essential! Informatie is belangrijk, maar feedback is essentieel! Our journey to write a general introduction to control and feedback started with the realisation that in our chosen field of study the proponents have taken little time to project the main ideas outside the community of the initiated. We are constantly - minded of the fact that there is no general awareness of control engineering, or c- trol technology, despite its ubiquity when we try to introduce ourselves as control engineers. Invariably this leads to A what engineer? response. We suspect that most control engineers do not even try to introduce themselves as such. It certainly is a poor communication starter. Colleagues, friends, collaborators often ask rather natural questions like So, what do you study in control? Is there a non-specialist introduction to the field? Can I read something to get a feel about this field of systems theory? What questions do you try to answer? What are the key results? In reply we can point to a wealth of technical lite- ture, rooted in mathematics, quite acceptable to some engineers or mathematics gra- ates, but rather too formidable a hurdle for most.