boltron · CC BY-SA 2.0

A Stanford computer scientist whose 1970s program SHRDLU could hold a conversation about a simple world of blocks, moving them on command and answering questions about what it had done — one of the first demonstrations that a machine could parse natural language in a bounded domain. He later co-directed Stanford's Human-Computer Interaction Group, shifting his research from artificial intelligence toward how people and computers actually work together, and taught the design course that shaped a generation of Silicon Valley engineers, including Google's founders.