Practice does not make perfect (Robert's Rule #1)

[Tweeted 2011-04-25]

I know it's an idiomatic expression, but it's never made sense to me...practice makes perfect? Really?!? If that's really the case then why have instructors at all? All of those teachers, coaches, mentors, et cetera, et cetera. Why not just follow Nike^® and "Just Do It"? In what was even worse, I had the mistaken impression as a young man that, since I was the only one who ever seemed to notice this rather odd inconsistency, I was horribly, drastically, wrong. Everyone knew practice makes perfect and said so, repeatedly. Then, in my first year of a graduate program in Management of Information Systems, one of my professors said "contrary to the popular idiom, practice does not make perfect; perfect practice makes perfect". Considering that I remember his exact words more than two decades later I suppose one might say the event held some sort of impact.

Now, I should probably mention that this thinking, this idea of our "practice" needing some element of perfection in order to be effective, came from someone who did not grown up in what we refer to as "Western civilization", but rather from someone born, raised, and educated in the "East". I feel I should mention this because the opposite idea, that any practice makes perfect, implied by our idiomatic expression has dominated our thought, as evidenced by the following experience.

When I was starting, long, long ago in a galaxy far away, I installed payment systems that used both computers and what we now call Point-of-Sale (POS) terminals and did the training. (For those who don't know, POS machines are little credit card machines that you now see everywhere.) In order for the system to work, it had to be connected to a telephone line so the little 1200 baud modem could dial out, connect to the company server, and transfer all the payment records. All easy peasy for the time...until it wasn't.

In one instance, everything appeared correct. All systems were up and running, training had been completed, a day's business was recorded and it was time to initiate the data transfer to complete the training and verify the system was working as designed. Unfortunately, the modem in the POS wouldn't work, so I began troubleshooting. Telephone handset worked, but none of the POS devices I had would work. When I asked the lineman from the telephone company to switch the tip and ring (polarity) on the circuit, I was not-so-politely informed that he had been installing telephones for more than 40 years and it was installed correctly. After he verified that the line had dial-tone, he departed, I took out my screwdriver and switched the tip and ring and bang, pow, the POS modem got a dial-tone, connected, and transferred the data in under 5 minutes.The lineman's practice was not perfect, and in fact, it was likely that the majority of his 4 decades of practice was incorrect.

So, when I look at what these two experiences (the professor confirming my long-held belief and the lineman confirming its opposite) teach me, this is what I am left with: practice does not make perfect, perfect practice makes perfect (Robert's Rule #1) and its corollaries that (1) we learn from mistakes, so perfect practice is not possible and (2) anybody, even an expert with 4 decades of experience can make a mistake that a n00b can fix.

Three simple statements that everyone in the tech industry should recognize, and one simple idiomatic expression that we should all stop using.