As in Science, and in Life, critical thinking is a vital part of an engineer’s mental toolbox. One basic tenet of critical thinking for an engineer is the simple question, does this make sense?
This question can be applied to almost any situation, idea, solution, or information. It is particularly useful (and necessary) when reviewing others’ computer generated or assisted calculations. More times than I care to remember have I been handed final reports that have gone through a checking process and look great, but which contain errors that I’ve spotted immediately just by asking that question. Yes, sometimes it takes years in the job to be able to spot those things quickly, but even if you don’t have the instinct of the numbers yet, a few minutes with a scratch pad and calculator will go a long way to answering the question.
Even some quick Nuke-math (as some call it in the Navy) done in your head can often uncover, or verify, whether the answer is in the right order of magnitude or if it is the right sign or direction, or if the units are right (or if the formulas will produce the units shown in the answer), or if the initial assumptions are reasonable, or if they included all the factors and variables in the calculations.
I remember one particularly egregious case where a report was submitted with no indication of anything wrong but which indicated that the ship had negative stability and should have been floating upside down at the pier if the report had been right. Here they never asked the question when they saw the negative number and the didn’t understand the significance of that number being negative. A fail on both accounts.
So keep asking that question—no matter how the information is presented or who gave it to you. And don’t stop when you leave the office. Does that total at the grocery store or restaurant make sense? Or the claims of that infomercial? Or the latest idea from that politician?
One simple question and a modicum of common sense can do great things.
What do you think? Post a comment below if you’ve got something to say.