Contradictions

The situation where an attempt to improve one feature of a system causes another feature to degrade is called a contradiction.

Examples:

• When the strength of a mechanical object is increased, its weight increases as well.
• Increased acceleration in an automobile also increases fuel consumption.

• A pen tip should be sharp to draw legible lines, but blunt to avoid tearing the paper.
• Aircraft landing gear is necessary for takeoff and landing, but is undesirable during flight.

The conventional way to deal with a contradiction is to look for a compromise or trade-off - however, there are many examples of solutions that resolve contradictions. This means that methods for satisfying contradictory requirements exist and can be exploited.

The ability to formulate contradictions is an important aspect of inventive problem solving. However, facing contradictions in our professional and personal lives can also creates psychological stress, as illustrated by this anecdote:

Ivan Pavlov, the Nobel Prize-winning physiologist, performed the following experiment: A dog was shown a circle and at the same time given a reward. When shown an ellipse, the dog received an electrical shock. As result, the dog learned to recognize a circle and ellipse. The next step in the experiment was to show the dog a circle, then slowly change it to an ellipse. As this change was taking place, the dog became increasingly stressed. It was confronted with a contradiction - whether to expect a reward or a shock. The result: the dog had a heart attack.

Fortunately, I-TRIZ provides us with tools to address contradictions and thus diminishes rather than increases the stress associated with them.