Case Study: ELIZA

📘 Case Study: ELIZA

1. What is ELIZA?

ELIZA is an early natural language processing (NLP) program developed in 1966 by Joseph Weizenbaum at MIT.

🎯 Its goal was to simulate a human-like conversation, particularly mimicking a Rogerian psychotherapist.

ELIZA is considered the first chatbot in AI history.

2. Purpose of ELIZA

• Explore human-computer interaction using natural language.
• Demonstrate that simple pattern matching could produce the illusion of understanding.
• Study how people emotionally react to machines that appear to understand them.

3. How ELIZA Works

ELIZA uses pattern matching and substitution techniques:

1. Analyzes user input using predefined rules.
2. Matches input against keyword patterns.
3. Applies a transformation rule to generate a response.

💬 Example: User: "I am feeling sad." ELIZA: "Why are you feeling sad?"

ELIZA does not understand the meaning — it simply mirrors the input in a clever way.

4. The DOCTOR Script

The most well-known script used in ELIZA is called DOCTOR, where ELIZA pretends to be a psychotherapist.

• This script works well because therapists often respond with open-ended, reflective questions.
• ELIZA's responses encouraged users to continue talking, creating the illusion of a meaningful conversation.

5. Example Interaction

User: I am unhappy.
ELIZA: I'm sorry to hear you are unhappy.
User: I need help.
ELIZA: What kind of help do you need?

6. Impact of ELIZA

7. Limitations of ELIZA

✅ Summary