Conklin's book is an interesting and informal discussion with the reader about the 5 Principles of Human Performance principle by principle, chapter by chapter. These 5 theroies about how humans perform in organiations are principles, the building blocks of Human Performance, through which we have established a new way to think about safety and reliability in our worlds. ...and changing the way we think about work is a vital step towards improvement.Work never stops and work is never normal. This idea would scare a mere-mortal manager, but an enlightened leader knows the power of continuous learning and improvement. Work is constantly in motion, therefore learning must continue. Work is never the same, therefore we never really know how work is being done. If we don't know how we perform work how will we know how we can improve?The 5 Principles of Human Performance are, in a sense, a repository of the central values of Human Performance. Keeping these principles at the core of our thinking, training, and practices will allow the basic building blocks of this philosophy to help organizational programs reduce the normal philosophical drift that is present and predictable in all safety programs. Having these espoused principles keeps us all honest and keeps our Human Performance effort on track and successful.