Principles are ways of successfully dealing with reality to get what you want out of life.
Ray Dalio, one of the world’s most successful investors and entrepreneurs, cites principles as his key to success.
It's hard to have an objective, open-minded, emotion-free conversation about performance if there is no data to discuss. It's also hard to track progress. This is part of the reason I created the Dot Collector. I also recommend thinking about other ways that people's responsibilities can be put in metrics. One example: You can have people note whether they did or didn't do things on checklists, which you can then use to calculate what percentage of tasks they complete. Metrics tell us whether things are going according to plan--they are an objective means of assessment and they improve people's productivity.