Like many nerds of A Certain Age, I remember my first encounter with ELIZA. Futzing around on an old Apple II Plus in Dr. Donnelly’s high school computer lab, I stumbled across a version of the program written in Apple BASIC.
“HI! I’M ELIZA. WHAT’S YOUR PROBLEM?” it beckoned, in bright green, all-cap ASCII.
Little did I know at the time that this wasn't the “real” ELIZA. It was a distant descendant of the original, written in the mid-1960s by the mercurial Joseph Weizenbaum in an ancient programming language called MAD-SLIP. Vanishingly few people have ever encountered the original. Its source code languished for decades in the MIT archives, stored on fading sheets of fanfold computer paper.
In truth, there never was just one ELIZA. Weizenbaum himself envisioned the application wearing many hats: a theater critic, a poet, a travel agent, even a “Regular Joe” who could make small talk about New England. That vision of a multi-purpose conversational agent has been overshadowed by the famous DOCTOR persona that has become all but synonymous with ELIZA. But the story of how the archetypal chatbot came to occupy such a central place in computing history is far more complicated than you might think.
Over the past few years, a team of researchers has been digging into ELIZA’s origins and the complicated legacy of its larger-than-life creator. I enjoyed the chance to speak with several of them about what they’ve uncovered for a new piece in Communications of the ACM:
Vivid demonstrations of projection