Eliza - the original chatbot

In today's world of artificial intelligence (AI), where chatbots like ChatGPT and virtual assistants like Siri and Alexa have become household names, it's easy to forget the humble beginnings of AI.

It all began with Eliza, the first chatbot, which was developed in the mid-1960s. Although basic by today’s standards, Eliza was a groundbreaking experiment that paved the way for decades of innovation in human-computer interaction.

What Is Eliza?

Eliza is a computer program created in 1966 by Joseph Weizenbaum, a computer scientist at the Massachusetts Institute of Technology (MIT). Eliza was named after Eliza Doolittle, the fictional character in George Bernard Shaw's play Pygmalion. The program was designed to simulate human-like conversations. Eliza was capable of engaging in text-based dialogues by analysing user input and making responses based on simple pattern-matching techniques.

Eliza's most famous script was the DOCTOR script, which simulated the conversational style of a Rogerian psychotherapist. The program often turned the user's statements into reflective or open-ended questions, creating the illusion of understanding.

How Did Eliza Work?

Eliza's functionality was based on a straightforward algorithm that identified key phrases in a user’s input and generated a predefined response. Its core relied on:

1. Pattern Matching Eliza would scan the input for specific patterns or keywords, such as 'mother', 'feel' or 'always.'
2. Transformation Rules Once a keyword was detected, Eliza applied transformation rules to generate a response. For instance:
   • User: 'I feel sad.'
   • Eliza: 'Why do you feel sad?'
3. Deceptive Simplicity
   By rephrasing or reflecting questions back to the user, Eliza created the impression of understanding, even though it had no real comprehension.

Why Was Eliza Significant?

1. A New Era of AI Eliza marked one of the first attempts to make computers 'converse' in a way that felt natural to users. It was a revolutionary demonstration of how computers could simulate aspects of human communication.

2. Psychological Impact
   Users often felt emotionally connected to Eliza, even though they knew it was a machine. Weizenbaum himself was surprised by the depth of emotional responses Eliza elicited, especially from those who sought therapeutic comfort in its replies.

3. Human-Computer Interaction
   Eliza highlighted the potential—and the limitations—of AI in mimicking human behaviour. It sparked debates about the ethical implications of creating machines that could exploit human emotions.

Weizenbaum’s Concerns

Although Eliza became a significant milestone in AI, Weizenbaum was deeply troubled by how people interacted with the program. He feared that users might attribute too much intelligence or empathy to machines. In his book, Computer Power and Human Reason, Weizenbaum warned against blindly trusting computers to make decisions in areas requiring genuine human judgment.

Eliza’s Legacy

Eliza's design principles laid the foundation for future advancements in AI and natural language processing (NLP). It inspired the development of subsequent chatbots, including:

• PARRY (1972) Simulated a person with paranoid schizophrenia.
• A.L.I.C.E. (1995) Built on Eliza's concepts with more complex algorithms.
• Modern AI  ChatGPT and other advanced systems owe their origins to the conversational frameworks introduced by Eliza.

Even decades later, Eliza remains a fascinating reminder of how simple systems can create profound experiences. Its influence can be seen in modern applications, from virtual therapists to customer service bots.

Last year, Eliza even outperformed the free version of ChatGPT in the Turing test which requires a group of people to judge whether they are communicating with a human or a computer.

Conclusion

Eliza was much more than a simple program—it was a vision of what human-computer interaction could become. While it lacked true understanding, its ability to mimic conversation demonstrated the potential of AI to engage with people in meaningful ways. Today’s chatbots, with their vast datasets and deep learning algorithms, are far more advanced. Yet, the principles behind Eliza continue to inform and inspire the field of conversational AI.

Joseph Weizenbaum’s creation was a pioneer, sparking a technological revolution that continues to shape our digital world. Eliza's legacy reminds us that even the simplest innovations can leave a lasting impact.

If you would like to try Eliza for yourself, you can use my online program or install my web app.