ELIZA

An interesting Hacker News thread popped up — ELIZA Reanimated: Restoring the Mother of All Chatbots to One of the World’s First Time.

ELIZA, created by Joseph Weizenbaum at MIT in the early 1960s, is considered the earliest chatbot. He programmed it in Michigan Algorithm Decoder-Symmetric List Processor (MAD-SLIP) on MIT’s Compatible Time-Sharing System (CTSS) operating system, on an IBM 7094. The original ELIZA was discovered in a printout in Prof. Weizenbaum’s papers at MIT’s Institute Archives, including an early version of its famous DOCTOR script, a nearly complete version of the MAD-SLIP code, and various support functions in MAD and Fortran Assembly Program.

The paper (pdf) describe the reconstruction and reanimation of this original ELIZA on a restored CTSS, running on an emulated IBM 7094. The entire stack is open source, so that any user of a Unix-like operating system can run the world’s earliest chatbot on their own version of a pioneering time-sharing system.

The Eliza Effect borrowed its name from ELIZA the chatbot. This effect is first defined in Fluid Concepts and Creative Analogies: Computer Models and the Fundamental Mechanisms of Thought as humans’ assumption of which computer programs understand the user inputs and make analogies. However, it has no permanent knowledge but ”handling a list of ‘assertions’.”

ELIZA was inspired by Rogerian psychotherapy, a conversational style that encourages the speaker to elaborate on their own thoughts and feelings. Ironically, ELIZA’s intelligence wasn’t deeply cognitive but was rather skillfully superficial. Instead, she cleverly picked up keywords from your sentences and reflected them back as questions, making the conversation flow as if a thoughtful therapist was listening. Imagine chatting with a friend who nods and prompts you to keep talking—without ever truly grasping the nuances of your story.

The charm of ELIZA was precisely her simplicity and the uncanny way people found emotional connections with her. She paved the path for every chatbot we interact with today, from customer support bots to sophisticated assistants like Siri or ChatGPT.

For computer lovers, programmers, and tech enthusiasts, ELIZA remains a delightful memory of how far we’ve come and how a few simple lines of code changed our relationship with technology forever.

You can tinker with an ELIZA replica/clone right in your browser source.