Chat bots are computer programs that can converse with humans in natural language. They use Artificial Intelligence Markup Language (AIML) to represent knowledge and respond to patterns in user input with predefined responses. The first chat bot, Eliza, used knowledge representation and pattern matching to simulate a conversation. A chat bot has an AIML interpreter that looks for patterns and selects the appropriate response from the AIML file. Chat bots can be trained to act as expert systems and be used for customer service, answering common queries to replace humans for repetitive tasks.

1. Chat Bots
Sachin Sharma
C.S.E. 4th
year
1428010010

2. Introduction
 Chat Bot: A computer program that can talk to humans in
natural language!
 Uses Artificial Intelligence Markup Language (AIML) to
represent knowledge.
 Can replace a human for monotonous jobs of answering
queries, e.g. E-help desk.

3. How It All Started
 Eliza – the first chat bot made by Joseph Weizenbaum.
 Working of Eliza is based on
– Knowledge Representation
– Pattern Recognition
– Substitution of key words into known phrases.

4. How does it respond
 Looks for certain patterns of words in the user's input.
 Replies with pre-determined output, if the pattern is
matched.
 Needs to have an idea of what the user will chat
 Has suitable responses defined in the AIML file

5. Architecture of a Chat Bot
Responder
AIML Interpreter
AIML Objects
A Chat Bot

6. Knowledge Representation
 Types of AIML objects
– Topics
– Categories
 E.g. :
<aiml>
<topic name=“the topic” >
<category>
<pattern>PATTERN</pattern>
<that>THAT</that>
<template>TEMPLATE</template>
</category>
</topic>
</aiml>

7. Example AIML Object
 AIML Object
<category>
<pattern>HELLO</pattern>
<template>Hi there!</template>
</category>
 Chat Sequence
User: Hello!
Chat Bot: Hi There!
<category>
<pattern>YES</pattern>
<that>DO YOU LIKE MOVIES</that>
<template>What is your favorite movie?
</template>
</category>
Chat Bot: Do you like Movies?
User: Yes
Chat Bot: What is your favorite
movie

8. Topics and Categories
 Topic: an optional top-level element that contains category
elements
 Category: consists of an input question (pattern) and an
output answer (template).

9. Turing Test
 Alan Turing proposed the Turing Test as a replacement for
the question “Can machines think?”
 Turing's aim is to provide a method to assess whether or not a
machine can think.
 The test
– A man (A), a woman (B) and an interrogator (C) chat.
– The objective of the interrogator is to determine which of the other
two is the woman
– If a machine (bot) chats instead of A or B and fools the interrogator,
it has passed the Turing test.

10. Can It Answer All My Questions?
 A Chat Bot has a limited number of patterns and responses.
 The AIML structure supports regular expressions
 In AIML, you can define recursive categories.
 The bot may sometimes give funny replies, but that depends
on the AIML spec, i.e. Its brain!

11. How to build a bot of your own
 Components – An AIML Object Spec, AIML interpreter,
and a responder!
 The brain is the AIML file, that defines patterns and
corresponding replies
 A bot can be trained to be an Expert System about a special
theme – large data!
 Training data – Yahoo Chat!

12. What is a Chat Bot useful for?
 Commercial chatter bots to help customers
– At web-shops and e-commerce sites.
– Bots to receive complaints from users, online
 An interactive (talking) encyclopedia.

13. Thank You