American Scientist

To the Editors:

Many thanks for Henry Petroski’s seemingly mundane article on failure analysis (“Solving Failures Around the House,” January–February), which I contemplated when our dishwasher would not drain. Surely it was a failed controller, or something with the drain pump? It was neither, and in solving the mystery I realized how related this detective work is to successful scientific inquiry. We form hypotheses about nature and eliminate them by testing assumptions or corollaries; this process is most efficient if we can eliminate groups of similar hypotheses using the “strong inference” approach that the late biophysicist John R. Platt wrote about in Science in 1964. Often the best answer comes from an unexpected direction, calling for an open mind and that mysterious (often unconscious) creative process Petroski refers to as “a good guess.”

Nickolas M. Waser
Tucson, AZ