Modelling

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Modelling

• Concepts of Software Development

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What is a Model?

• Example

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What is a Model?
A model is a representation of something else
public class car String colour String
ModelName double price Person owner
String registration int milage
A model is an abstraction
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What is a Model?
Contains the essence of the thing being modelled.
Leaves out what is not essential
The behaviour of the model should be close to the
behaviour of the thing being modelled.
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Abstraction

• Choosing what to include and what to leave out of
  a model is the process of abstraction.

Consider a friend. What are the important
aspects of your friend?
You may have thought of A name A shared
experience What they look like
Did you include the following Blood Group DNA
profile Mothers Maiden Name Weight of Liver
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Abstraction
All models held in a computer are abstractions.
Almost all activities in Software Development use
models and the process of abstraction. All
programs are models.
Activity Write down a description of a Chair.
Abstract ideas can be tricky.
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Software Development
Requires modelling of real things so that they
can be represented in a computer. e.g. A
Spreadsheet
Database
Web Page
Program
Object Modelling
Process Modelling