Uncertain about uncertainty?
How uncertain are we of our uncertainties? What risks are there of risks? Sometimes our analysis goes too deep. Sometimes we build predictions of predictions that predict reality, introducing information that really was never there. Yet, isn't the uncertainty of uncertainty intriguing, illusive and important, in understanding our climate, our economies our science and our engineering?
In November just past, at the Boston Aquarium, climatologist Prof. Timothy Palmer spoke most effectively of uncertainty in predicting climate change. His message - there is no one single predicted outcome, but rather a collection of scenarios, each with its own likelihood. When developing policy, we should account, not for the cost of the most likely and expected outcome, but rather for the expected cost considering the chances of all outcomes.
In selecting stocks or projects we rely upon past returns as some indicator of how they will perform. In judging risk, we can look at the risks of similar stocks or projects in the past. However, since this estimated risk is based upon information past, it too is uncertain, and we must face being uncertain of being uncertain.
Arguably, science and engineering are most quantitative in assessing what is uncertain. We run experiments many times, as in discovering the Higg's Boson, and can provide a number to indicate to what degree we are certain. Meanwhile, we must take care that what we observe is not because of what we expect to observe or how we would like to observe it.
Society is challenged by uncertainty and many recursions thereof (uncertain uncertainty, uncertain uncertain uncertainty etc.). I believe engineers can make great contributions in establishing and communicating an understanding of these recursions. Engineers have the rigour required for deep understanding but also the innovation to apply known principles in new ways. Understanding uncertainty, in our societies and our economies, is the challenge of this century. Engineers will make the difference. Of that, I am certain.
Timothy Palmer, 2012. Predicting Climate Change in a Chaotic World: How Certain Can We Be? Youtube
Cox, Brown and Pollock, 2012. When is Uncertainty About Uncertainty Worth Characterizing? Interfaces.
CERN, 2012. Atlas.
For a nice cartoon on climate change and world politics see KAL's cartoon from The Economist