Black Box Optimization

Engineers and scientists like to know how things work. They seem to be born with an inner drive to understand the fundamental nature of things. So, naturally, they may have some reservations about using an algorithm if the way it functions is not clear.
Black box
When we can’t see the details about how something works, we often refer to it as a black box. Input goes in and output comes out, without any knowledge of its internal workings.

Black box sometimes has a negative connotation, because knowing how something works is usually a good thing. But if we evaluate the idea of a black box, we find that many common processes and tools – including the human brain – actually fall into this category.

For example, most users of the finite element method have some basic knowledge of its underlying mathematical theory. But many of the element types available in commercial software packages are based on advanced formulations that few users completely understand. These advanced formulations are necessary to overcome deficiencies in the element behavior, and users can apply them accurately without knowing all the mathematical formalities. There are many similar examples in computational mechanics.  Continue reading

The Limits of Intuition

The human brain is capable of making quick and effortless judgments about people, objects or ideas that it has not previously encountered. This sort of unreasoned insight is often called intuition. In his article, “The Powers and Perils of Intuition” (Scientific American MIND, June 2007, pp 24–31), David Myers describes two types of influence that shape our intuition.

Fork in the roadThe first is the development of mental shortcuts, or heuristics, which allow us to make snap judgments, often correctly. For example, our intuition tells us that blurry objects are farther away than clear ones. This is often a helpful assumption, except that on foggy mornings, a car in front of you may be much closer than intuition tells you it is.

The second influence on intuition is “learned associations” or life experiences that guide our actions. This explains why we may be suspicious of a stranger who resembles someone who once threatened us, even if we do not consciously make the association. Similarly, an experienced engineer can often quickly solve a problem that resembles one he worked on many years ago, even if the details of that project are mostly forgotten.   Continue reading