Lawrence Tesler, a pioneering computer scientist who helped make it easier for users to interact with computers, whether cutting and pasting text or selecting text by dragging a cursor through it, died Feb. 23 at his home in Portola Valley, CA. He was 74.

Mr. Tesler worked at a number of Silicon Valley’s most important companies, including Apple under Steve Jobs. But it was as a young researcher for Xerox at its Palo Alto Research Center in the 1970s that he did his most significant work: helping to develop today’s style of computer interaction based on a graphical desktop metaphor and a mouse. Mr. Tesler was passionate about simplifying interaction with computers, the New York Times said.