Inventor of ‘copy-and-paste’ impacted the digital world

Larry Tesler, who invented and named the “cut, copy and paste” commands on computers, an indispensable part of the everyday operation of digital devices, died Feb. 16 at his home in Portola Valley, Calif. He was 74.

The death was confirmed by a brother, Alan Tesler, who declined to specify the cause.

Mr. Tesler, who worked for companies including Xerox, Apple, Amazon and Yahoo, devoted much of his career to the idea of making computers practical, inexpensive and easy to use.

During the 1970s, he worked at Xerox’s Palo Alto Research Center in California, which produced many breakthroughs in computer technology. Among other advances, Mr. Tesler was credited with helping develop the terms “user-friendly” and “WYSIWYG,” for “what you see is what you get,” to describe the goal of having computer printouts be the exact duplicate of what is seen on a screen.

He also devised what is known as Tesler’s Law, a tenet holding that, in any computing system, there is a level of technical complexity that cannot be reduced.

It was Mr. Tesler’s work on the Gypsy word processor at PARC during the 1970s that turned out to have the greatest utility and long-term impact. With his interest in simplicity, he sought ways to make computers more interactive for consumers, a notion called “user interface” in computer design. In developing his designs and ideas, Mr. Tesler often asked ordinary users — rather than computer experts — what they wanted their machines to do.

For his best-known innovation, Mr. Tesler adapted an age-old practice of schoolchildren — cutting out pictures and pasting them in scrapbooks — to computers. At first, he thought the term “cut-and-paste” would apply strictly to design and visual images.

Mr. Tesler and another computer scientist, Tim Mott, “did user testing at every stage of the development. He was the one that came up with the idea of the double click to select a word.”

By pressing or “clicking” on a computer mouse and then dragging the cursor across an image or a block of text, the selected material could be highlighted, or “cut.” A similar procedure with the mouse would allow that text to be copied or “pasted” onto another part of the document on the screen.

The technical advance was not put into widespread practice until years later, after Mr. Tesler had left Xerox for Apple. The cut-copypaste command was incorporated into Apple’s Lisa computer in 1983, then became a standard function on the Macintosh operating system, which was introduced a year later. It is now an essential element of every digital device.

Mr. Tesler worked on many elements of computers now taken for granted, such as the amount of finger pressure needed to click a computer mouse.

Survivors include his wife, Colleen Barton, of Portola Valley; a daughter from a marriage that ended in divorce; and two brothers.