Chat Bots Welcome to the world of living

Chat Bots Welcome to the world of living people and artificial intelligence entities called bots! Ruta Mehta Mugdha Jain Jeetendra Mirchandani

Questions We’ll Answer A Chat Bot… l What is it? Who wants it? Why? l Since when is it around? l How does it work? l How do you test it? l Can it answer all my questions? l Can I make one of my own? l Where can I put it to work?

Introduction l l l 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.

How It All Started l l Eliza – the first chat bot made by Joseph Weizenbaum. Eliza Effect – l tendency of humans to attach associations to terms from prior experience. Working of Eliza is based on – – – Knowledge Representation Pattern Recognition Substitution of key words into known phrases.

How does it respond l l 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

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

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

Example AIML Object l AIML Object <category> <pattern>HELLO</pattern> <template>Hi there!</template> </category> l 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

Topics and Categories l l l Topic: an optional top-level element that contains category elements Category: consists of an input question (pattern) and an output answer (template) Types of Categories – – – Atomic Category Default Category Recursive Category

Atomic Category l l Contains patterns that does not have wildcards “*” or “_”. Example: <category> <pattern>10 DOLLARS</pattern> <template> wow, what a cheap </template> </category> l Conversation: User: This watch is for 10 dollars Chat Bot: Wow, what a cheap watch!

Default Category l Contains patterns that have wildcards “*” or “_”. Example: l Conversation: l <category> <pattern>10 *</pattern> <template> It is ten. </template> </category> User: 10 dollars. Chat Bot: It is ten.

Recursive category l l l Template calls the pattern matcher recursively Uses <srai> tag, that stands for symbolic recursion artificial intelligence For example, In English there are different ways to ask about X: Describe x? Tell me about X? Do you know what X is? The knowledge is stored in the simplest way. Whatever the question is, it will be reduced to category like <What is>.

Input normalization l Substitution normalizations Abbreviations such as "Mr. " may be spelled out as "Mister" to avoid sentence-splitting at the period in the abbreviated form. l Sentence-splitting normalizations Rule: break sentences at periods. It relies upon substitutions performed in the substitution phase. l Pattern-fitting normalizations Remove all characters that are not normal characters; like converting lowercase letters to uppercase.

Example <category> <pattern>HELLO</pattern> <template> <random> <li>Well hello there!</li> <li>Hi there. I was just wanting to talk</li> <li>Hello there !</li> </random></template></category> <pattern>WHAT IS 2 *</pattern> <template><random> <li>Two. </li> <li>Four. </li> <li>Six. </li> <li>12. </li> </random></template></category> <pattern>_ WHAT IS 2 AND 2</pattern> <template> <sr/><srai>WHAT IS 2 AND 2</srai> </template> </category> <pattern>HALO</pattern> <template> <srai>HELLO</srai> </template> </category>

Question : Halo, What is 2 and 2 _ What is 2 and 2 </sr> <srai> WHAT IS 2 AND 2 </srai> HALO WHAT IS 2 AND * HELLO WHAT IS 2 * Well hello there! Hi there. I was just wanting to talk. Hello there ! Answer : Two Four Six 12 Hi There! Six

Graph-master – an example interpreter l l l AIML interpreter: tries to match word by word to obtain the largest pattern matching which is the best one. Graph-master: an interpreter that models this behavior Contains a set of nodes called Node-mappers. Node-Mappers : map branches from each node where branches represent the first words of all patterns. Each leaf node contains a template.

Flowchart for Pattern Matching yes Node-mapper Contains ‘_’? Search sub-graph rooted at child node linked by ‘_’ Try all remaining suffixes of input following ‘X’ no no Node-mapper Contains ‘X’? yes Search sub-graph rooted at child node linked by ‘X’ using input ‘tail’ Match? no Node-mapper Contains ‘*’? yes Match? yes no yes Search sub-graph rooted at child node linked by ‘*’ Try all remaining suffixes of input following ‘X’ Match? yes

Some Observations l Priority order at every node: – – – l l l ‘_’ wildcard, followed by an atomic word, followed by ‘*’ wildcard. Patterns need not be ordered alphabetically The matching is word-by-word, not category-bycategory Highly restricted form of depth-first search

Turing Test l l l 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.

Can It Answer All My Questions? l l 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!

How to build a bot of your own l l l Components – An AIML Object Spec, AIML interpreter, and a responder! A Chat Bot represents and models a character. 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!

What is a Chat Bot useful for? l l l Commercial chatter bots to help customers – At web-shops and e-commerce sites. – Bots to receive complaints from users, online An interactive (talking) encyclopedia. Chatter bots administrating IRC-channels and Hotline server. The Psychiatrist – the famous pronoun reversal trick Starship Titanic, a game created by the famous writer Douglas Adams along with Terry Jones

Questions We Answered A Chat Bot… l What is it? Who wants it? Why? l Since when is it around? l How does it work? l How do you test it? l Can it answer all my questions? l Can I make one of my own? l Where can I put it to work?

Clarifications l How powerful is Java. CC-built parser? – l Powerful than a yacc generated parser? – – l AIML is connected to a system that allows for learning new patterns and putting them into a context Context sensitive Learning ? – l As long as one can use Java. CC's look-ahead specification to guide the parsing where the LL(1) rules are not sufficient, Java. CC can handle any grammar that is not left-recursive. Dialogue Corpora can be used to train a Chatbot! (See References) Intelligent? – Even Turing tests have different levels and yet cannot finally decide whether the system is intelligent or not. Nowadays a system is considered to be intelligent if it is able to mimic intelligent behaviour (e. g. within a specified domain).

Thank You

References l l l The Anatomy of A. L. I. C. E. : Dr. Richard S. Wallace, http: //www. alicebot. org/anatomy. html Artificial Intelligence Markup Language (AIML), A. L. I. C. E. AI Foundation, http: //alicebot. org/TR/2001/WD-aiml/ AIML Interpreter Overview 2004, http: //www. aimlbots. com/en/aimlinterpreters. html Computing machinery and intelligence, Alan Turing [1950], http: //www. abelard. org/turpap. htm Using Dialogue Corpora to Train a Chatbot (Bayan Abu Shawar, Eric Atwell) http: //www. comp. leeds. ac. uk/andyr/research/papers/techreport 2003_02. pdf

Project Proposal l Extension to Chat Bot, that will reply emails Will maintain a chat session in terms of email-session-id Can be useful for auto replying to emails that have a common reply, related to the question in the email – e. g. – help@cse - email to register your complaints!