Q&A #1154

Teachers' Lounge Discussion: Front End Estimation

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From: Barry

To: Teacher2Teacher Public Discussion
Date: 2002091618:09:42
Subject: Re: Re: Re: guessing vs estimation

Point taken, Peter. Here's your question: 

What is the distance from Toronto to Vancouver? 

Remember, "Either you have the right answer or wrong answer."

"Estimating" and "guessing" are not the same thing at all.
Unfortunately, many of us adults, parents, teachers, and others do not
(or cannot) distinguish between them, and are too loose in our use of
the words.

A guess is simply a guess, and if the local building contractor
presented you with a 'guess' at how much it was going to cost you to
build your new house, you'd still be in the dark on what the actual
cost would be, and the builder, if he guessed wrong would likely go
broke through either accepting jobs for which he'd guessed far too low
or losing jobs for which he'd guessed too high.

An actuary, guessing how much his company would pay in claims that
year, and using that guess to set his company's insurance rates, would
be in the same (sinking) boat.

Neither of these people make 'guesses.' Both, if they are to stay in
business for any length of time, are skilled estimators. No one can
tell to the last penny how much it will cost to build a
house--materials prices alone change with market conditions. Nor can
any insurance actuary tell you exactly how much his company will pay
out this year.

The simple fact that there are contractors who have succeeded and
insurance companies that survive attests to the estimating skills of
the people making the above estimates (NOT 'guesses').

In the elementary schools, the key questions are "How did you get that
answer?", and "Why do you think it's a reasonable answer?" Childen who
are taught that an estimation is 'just a guess' will be stuck with
that explanation, and won't learn to make reasonable (and reasoned)


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