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Queen's University

Whimsey - The Parable of the Lawnmowers

Structured Clinical Judgment in Risk Appraisal: An idea whose time has gone: The Parable of the Lawn Mowers*

Vernon L. Quinsey, Ph.D.
Queen’s University at Kingston, ON

So I go to Canadian Tire and pick up a lawn mower for a couple of hundred bucks. Its operation is simple enough that, following the application of a little authoritarian persuasion, I can sit on my deck sipping mint juleps and increasing the likelihood of my developing a malignant melanoma while supervising my kids cutting the lawn.

One day a guy comes to my door with a very fancy looking lawn mower. Now this lawn mower comes with a tweed or pinstripe dust cover and has a unique feature–the machine that drives the blades is mounted on springs! This feature means that the operator must apply exactly the right amount of downward pressure to cut all the grass at the same height. Difficult? You bet. But the operator has trained for eight years (actually mostly in the ethics and philosophy of lawn management) and is now a bored certified and registered grass height consultant who can commit the controlled act of mowing as long as he uses tasteful fonts in his advertising. In addition, the operator has mowed court house and prison lawns all over North America and knows what he’s doing.

So I ask him–“how high will you cut my grass?” He says, “How high would you like it? Very high, moderately high, or low?” “Well,” I say “How high is moderately high?” “Well, you know,” he replies, “....moderate.” “How many inches is moderate?” I say, betraying my age. He smiles secretively. “That all depends on how hard I’m pushing.”

“So how consistent will ‘moderate’ be across my lawn? Right now I cut it all at exactly two inches.” “We’ve looked into this in great detail.” he says. “Our spring loaded model in the hands of a bored certified operator is almost as consistent as the completely mechanical ones. And you know what?” he confides, “The newer models have shorter and stiffer springs that make them just as good as the mechanical models in some studies.”

As prestigious and dynamic as this guy is, I can’t afford to pay him to cut my lawn–he’s just too expensive. However, for only ten times the cost of my old lawn mower, he’ll run a training workshop for me in the use of the spring-ed machine in the privacy of my own backyard. I think there’s a living to be made here and I’m thinking about it. As to capital investment, all I have to do is add four springs to my old lawn mower.

*A French version of the parable, entitled “Il faut que je meau de lawne avec les petites spirales de fer ou les bandes de latex” is permanently unavailable from the author.


Kingston, Ontario, Canada. K7L 3N6. 613.533.2000