Guidelines to create an ontology

transcript

Guidelines to Create an Ontology

Presenters :-

• Nisitha Manukulasuriya

• Rajith Premabandu

• Isuru Dilshan1

Overview• Designing a good Ontology

• Methods

• Basic Idea

• Ontology’s content

• Explanation of the guidelines by examples

Content• What is an Ontology

• Why Ontology ?

• What is in Ontology

• Methodology

• Basic Ideas

• Building the Ontology

• Taxonomy Evaluation

• E commerce Ontology Example

• Banking Ontology Example

What is an ontology

• “An ontology is a formal, explicit specification of a shared conceptualization”

• conceptualization

• explicit

• formal

• shared

• “An ontology is a formal, explicit specification of a shared conceptualization”

• conceptualization

• explicit

• formal

• shared 4

Why ontology ?

• Share common understanding of the domain and the related information

• To reuse knowledge

• To analyse domain knowledge

What is in Ontology

• Classes

• Relation

• Attributes

• Formal axioms

• Functions

• Instances 6

Methodology

• Define concept

• Organize them to taxonomy

• Define relations among the classes

• Define attributes and their values

• Define instances

• Define axioms and function7

Basic ideas

• Yours will be different from mine

• Iterative process

• Initially, start with nouns and verbs

• A noun will be a class, attribute or instance

• A verb will be the relation

• Iterations are needed to further clarification8

Building the ontology

• Determine the domain and the scope of the ontology

• Which domain are you thinking of?

• Is it going to be just one, or will you need different sub ontologies to make it clearer?

• Who will use the ontology?

Building the ontology …• Sources to use

• Experts

• Ask everything want to know

• Always keep manners

• Grab their terminology

• Documents

• literatures, documents, technical information, etc.

• Highlight underlying nouns and verbs

• Existing ontologies

• You are not the first one to think about that domain

• Existing ontologies can be fully or partially reused 10

Building the ontology …

• Enumerate important terms

• List all nouns and verbs

• For each noun note down

• name, synonym, a natural language description, source

• Decide whether the noun is a class, attribute or instance

• Verbs will end up as relations

• The iterative process will may uncover some other concepts too

Building the ontology …• Classify the concepts in a hierarchy.

• Use either top-down or bottom-up or combination of processes

• Hierarchical relations

• Subclass

• Disjoint decomposition

• Exhaustive decomposition

• Partition 12

Building the ontology …• Define relations

• Describe each hand made diagram and the relations in detail

• Define attributes

• Well defined type is an attribute, not a class

• Attach the attribute to the most general class/concept that can have that property

• Define attribute type13

Building the ontology …

• Define attributes …

• Try to define range, value, precision, related classes

• Define instances

• A specific noun

• Described in detail

Taxonomy Evaluation

• Class definition evaluation

• Synonyms for the same concept do not represent different classes

• A class is not only real entities in the domain

• Keep a balance with subclasses

Taxonomy Evaluation …

• Class Hierarchy

• Avoid class cycles

• Be careful of classifying classes where they do not belong

• Careful with your classification

• Careful with incompleteness of taxonomies

• Redundancy

• Other Hints

• Forget the implementation level

• Do not use “reserved” words in your names

• Choose a naming convention

• Limit the scope

Up to here

• What is an Ontology

• Why Ontology

• What is in Ontology

• Methodology

• Building an Ontology

• Taxonomy Evaluation

Example 1E-Commerce Ontology

E-commerce Ontology• What is e-commerce ?

• Description

• E commerce is used via computer networks such as internet. Several organizations involve in this process. Venture capital firm supplies Venture Capital ,financial support to establish such companies. Venture capital invests a large amount of currency to enable startup for a company. Company is also an organization that issues shares and shareholders buy shares to own a part of the company. A Share is an unit of capital that has price. CEO is a person who manages the company. A Company consists of B2B and B2C companies. A B2B transaction has an amount which is higher than B2C transactions.

Listing NounsListing Verbs

NounName

Synonyms Acronyms Description Source

Organization OrganisationAssociation

Org A commercial or industrial enterprise with a group of people ,systematically structured to accomplish an overall common goal.

Description

Person Human Unspecified individual with certain capabilities & responsibilities separate from others.

Description

VentureCapital

Financial supportFunding

VC Money provided by investors to start up firms in early stages of high potential .high risk growth companies.

Description

Venture Capital Firm

Venture Capitalist

Firms that provides start up or capitals / loans to promising ventures for long term growth potential.

Description

Company FirmCorporation

COCorp

Any business organization which has focus of gaining

profits.

Description

Unspecified individual with certain capabilities & responsibilities separate from others.

Money provided by investors to start up firms in early stages of high potential high risk growth companies

Firms that provides start up or capitals / loans to promising ventures for long term growth potential.

A commercial or industrial enterprise with a group of people, systematically structured to accomplish an overall common goal.

Any business organization which has focus of gaining profits

Describe nouns

Identify Concepts

• Concepts

• Organization

• Venture Capital Firm

• Venture Capital

• Person

• Company

• CEO

• Share

• Share Holders

• B2B

• B2C

Identify Relations

Venture Capital

amount:currency

CompanyShares

price:Currency issues

Shareholders

Venture capital Firm supplies

Name:stringmanages

Identify Attributes

• Class Venture Capital

• Amount : currency

• Period : date/time

• Class Company

• Name : string

• Address : string

• Property Names : string

• Profit : currency

• Capital: currency

Identify Instances• E.g.

• “Meg Whitman is the CEO of the B2C company ebay.com.”

Person

age:Integer…CEO

Name:string

Company

manages

Instance Of

Meg Whiteman

Instance Of ebay.com

Organization

Venture capital Firm

Venture Capital

amount:currency

Person

age:Integer…

Name:string

Shareholders

Shares

price:Currency

Company

B2CB2B

price: currency

managesissuesowns

supplies

Taxonomy Evaluation

• Every Class refers to only one noun.

• Haven’t used reserved key words.

• Class hierarchy well-balanced.

• Classes Don’t have Cycles.

• Used a Standard.

Up to now ……

• Identify Nouns

• Identify Verbs

• Define relations

• Identify Attributes

• Identify Instances

• Taxonomy Evaluation28

Example 2Banking Ontology

Banking Ontology

• Description

• There are several processes in a banking domain. An account holder owns several bank accounts. These accounts are identified with a unique account number. There are two types of accounts, current and savings. Bank account offers two kinds of loans. They are personal and educational loans. Bank account has compound interest and simple interest. A payment can be done to a bank account via cheque , cash or EFT. A payment has a date. When a payment is done a transaction is occurred. A transaction is a deposit or

withdraw. 30

Banking Ontology

• Description …

• An account holder is uniquely identified by an identification number and the address, monthly expense, NIC number are recorded. Current accounts should maintain a minimum balance and a penalty is calculated for the decrease of the minimum balance. Bank account calculate interest in various time periods. This vary with the bank. A cheque has a cheque number, amount, date, payee, bank name. A cash payment is done by the currency used. ETF payment has a sender and receiver account numbers.

Noun Synonyms Acronyms Description Source

Accountholder

- AH Member which administrates Global accounts.

Description

Bank Account

- BA financial account recording the financial transactions between the customer and the bank and the resulting financial position of the customer with the bank

Description

SavingsAccount

- A bank account that earns interest

Description

CurrentAccount

- These accounts are maintained by the corporate clients that may be operated any number of times in a day.

Description

Describe nouns

Identifying Concepts

• Cheque

• Cash

• EFT

• Method of Payment

• Transaction

• Payment

• Deposit

• Withdraw

• Compound interest

• Simple interest

• Interest

• Bank Account

• Account Holder

• Savings Account

• Current Account

• Loan

• Personal Loan

• Educational Loan

Identify Relations

Payment

amount:currency

Method of Payment

Is donevia

Account holder

id:String

Bank account

accNo:String

Bank account

accNo:String

amount:doubleperiod:int

Payment

amount:currency

Transaction

ammount:doubledate:date

occurs

Defining attributes

• Class Cheque• cheque number: String

• amount: currency

• Date: Date/Time

• Payee: String

• Bank: String

• Name: String

• Class Account holder• identification number :String

• address :String

• monthly expense :currency

• nic No:String

Account holder

id:String

Bank account

accNo:String

Savings

Current

minBal:float

Personal

houseExpence:double

Educational

purpose:String

Compound

calIntrest()

Simple

calIntrest()

Payment

amount:currency

Cheque

chequeNo:String

ammount:double

amount:double

sendAcknoledgement()

Transaction

ammount:doubledate:date

Deposit

Withdraw

Method of Payment

amount:doubleperiod:int

Interest

rate:float

Is donevia

Synonyms for same concept do not represent different classes

Keep a balance with subclasses Avoid class cycles

Be careful of classifying classes where they do not belong

Careful with your classification

Careful with incompleteness of taxonomies

Do not use reserved words

Redundancy

Gene Ontology

Summary

• Guidelines• What is an Ontology • Why Ontology ?• What is in Ontology• Methodology• Basic Ideas• Building the Ontology• Taxonomy Evaluation

• E Commerce Ontology Example

• Banking Ontology Example 39

References

• A Simplified Guideto Create an Ontology

• Julita Bermejo

• ASLab R-2007-004 v 0.1 Draft

• May 22, 2007

• An Ontology-based Method and Tool for Cross-Domain Requirements Visualization

• Nirav Ajmeri, Kumar Vidhani, Manoj Bhat, SmitaGhaisas

Tata Research Development and Design Centre

A Division of Tata Consultancy Services

References …

• http://www.geneontology.org

• Accessed on: 21 January 2012

• http://musicontology.com

• http://en.wikipedia.org/wiki/Axiomatic_system

• Accessed on: 22January 2012

• http://www.iqlue.com/Ontology.pdf

Any Questions ?

Guidelines to create an ontology

Technology