The New York Times has a nice obituary today of John E. Karlin, the lead industrial psychologist at Bell Labs for many years.

He worked at the interface between humans and machines — one of the first in a field in which so many of us work today.

Among this most important achievements, with which we all live every day, was deciding on the optimum layout of the phone touch pad, now obviously the model for almost all devices (except the earlier-designed calculator, which now befuddles us).

As described in the Times:

In 1946, a Bell Labs engineer, Rudolph F. Mallina, had patented an early model, with buttons arranged in two horizontal rows: 1 through 5 on top, 6 through 0 below. It was never marketed.

By the late 1950s, when touch-tone dialing — much faster than rotary — seemed an inevitability, Mr. Karlin’s group began to study what form the phone of the future should take. Keypad configurations examined included Mr. Mallina’s, one with buttons in a circle, another with buttons in an arc, and a rectangular pad.

The victorious design, based on the group’s studies of speed, accuracy and users’ own preferences, used keys half an inch square. The keypad itself was rectangular, comprising 10 keys: a 3-by-3 grid spanning 1 through 9, plus zero, centered below. Today’s omnipresent 12-button keypad, with star and pound keys flanking the zero, grew directly from this model.

Putting “1-2-3” on the pad’s top row instead of the bottom (the configuration used, then as now, on adding machines and calculators) was also born of Mr. Karlin’s group: they found it made for more accurate dialing.

The obit ends with a cute story about how his earlier work on facilitating the change from letter phone office codes, with their perceived organic feel, to all number phone codes, was widely publicized, and led to public opprobrium:

“One day I was at a cocktail party and I saw some people over in the corner,” Mr. Karlin recalled in a 2003 lecture. “They were obviously looking at me and talking about me. Finally a lady from this group came over and said, ‘Are you the John Karlin who is responsible for all-number dialing?’ ”

Mr. Karlin drew himself up with quiet pride.

“Yes, I am,” he replied.

“How does it feel,” his inquisitor asked, “to be the most hated man in America?”

As we work on human interfaces, we might remember that there are always, alternatives, and that testing is better than speculating.

By the way, would the Internet have taken off if we had had to learn IP numbers for websites and e-mail addresses?