Here’s a “must read” article for you HCI types:  a New York Times obituary for John E. Karlin, a Bell Labs industrial psychologist who is responsible for 7-digit dialing, the layout of the touch tone pad, the length of the cord on telephones (back when they had cords), and a slew of other “everyday things.”

“A generation ago, when the poetry of PEnnsylvania and BUtterfield was about to give way to telephone numbers in unpoetic strings, a critical question arose: Would people be able to remember all seven digits long enough to dial them?

“And when, not long afterward, the dial gave way to push buttons, new questions arose: round buttons, or square? How big should they be? Most crucially, how should they be arrayed? In a circle? A rectangle? An arc?

“For decades after World War II, these questions were studied by a group of social scientists and engineers in New Jersey led by one man, a Bell Labs industrial psychologist named John E. Karlin.”

Read this fascinating article here.