How Fast Do People Type?
Less than half the population of the world has the manual dexterity to wiggle their fingers at the speed of 50 words per minute or better.
–Dr. Alan Lloyd, seminal typing instructor.
Computer professionals often seem to have unrealistically high expectations of what the “average” typist can do. For example, according to this Wikipedia article (as of 2007-12-04)
An average typist reaches 50 to 70 wpm, while some positions can require 80 to 95 (usually the minimum required for dispatch positions and other typing jobs), and some advanced typists work at speeds above 120.
But as we shall see 70 WPM is an absurdly high “average”. 120 WPM means 12 strokes a second, or a split-time of 83mesc between keypresses. That borders on the physically impossible.
As Teresia R. Ostrach, President of Five Star Staffing, Inc. says,
After 27 years in the Staffing Industry, I’ve encountered just about every misconception regarding the performance of office workers. The most frustrating of these is the belief in what constitutes “average” typing scores.
“For years I tried to explain that 65 WPM is a lot faster than average, but I had no proof. After all, everybody knows what an average typist is, right? Somebody who types between 50 and 60 WPM? Well, isn’t it? Well, NO, it’s not!
Here are her findings:
Mean = 40 WPM = 240 characters/minute
Median = 38 WPM = 228 characters/minute
Standard Deviation = 16.7-WPM = 100 characters/minute
Notice that that out of the three thousand four hundred and seventy five applicants, not a single one could manage 120 WPM. And only the top 5% of applicants could manage 70 WPM or higher.
Typing Speed: How Fast is Average
4,000 typing scores statistically analyzed and interpreted
It’s an excellent paper. Short and accessible, yet relevant, authoritative, and eye-opening. Well worth the read. (Unfortunately it’s laid out poorly in the liked PDF. If someone has a more readable source I’d love to link to it).
But what’s more interesting to me is this chart:
Which shows an average error-rate of about 6% per word. Put another way, more then 1 out of every 17 words has a typo in it, which is kind of a big deal.
The error-rate is probably artificially high, because subjects were taking the test under a lot of pressure — it determined if they got a job or not! But even the best group of over-qualfied typists still had a 4% error rate; or a fumble on 1 out of every 25 words. And that’s significant.
The implications of a 4%-6% error-rate are enormous. If people are making that many errors, then good spellcheckers, and auto correctors are essential. If one out of every 17-25 words is mistyped, then long command-lines seem like a very bad idea, because something like one out of every 20 commands would be in-error. Systems should be able to gracefully recover from bad input; because they will be inundated with it.
It looks like the average typist is much slower, and makes more mistakes, then “folk-wisdom” leads us to believe.