L4-S1 Modeling Concepts 2003 SJSU -- CMPE Advanced Object-Oriented Analysis & Design Dr. M.E. Fayad, Professor Computer Engineering Department, Room #283I College of Engineering San José State University One Washington Square San José, CA

L4-S2 Modeling Concepts 2003 SJSU -- CmpE M.E. Fayad 2 Lesson 4: Modeling Concepts

L4-S3 Modeling Concepts 2003 SJSU -- CmpE M.E. Fayad Lesson Objectives 3 Understand Modeling concepts Using UML concepts Explore OO models

L4-S4 Modeling Concepts 2003 SJSU -- CmpE M.E. Fayad 4 Logical Forms  The same substance often take several forms.  ice, steam, water, snow, frost, fog are different forms of H 2 O  Some substances can be transformed from one form to another.  Not all of our studies are of material substances.  Speech, Writing, Geometry, Physics, etc.  But each area of human study acknowledges the existence of “good form”.  “Form” is thus equated with the existence of a pattern/order/consistency/regularity

L4-S5 Modeling Concepts 2003 SJSU -- CmpE M.E. Fayad 5 Structure  “Structure” is the way a thing/construct/form us built up from its parts.  Changing the structure’s content can lead to new forms.  Musical notes, part of a house, etc.  A given content may exist in several different forms.  But each area of human study acknowledges the existence of “good form”.  Conversely, a form may also appear in several different contents  In fashion, dresses can be made from different materials.

L4-S6 Modeling Concepts 2003 SJSU -- CmpE M.E. Fayad 6 Abstraction  “Abstraction” is the consideration of a form apart from its contents. Examples:  “roundness” is a property of a golf ball, a snow ball, a baseball, etc.  “hardness’ is a property of diamond, wood, steel, etc.  Abstraction can be improved upon by practice and study.  Abstract forms are discovered, and named, in the investigation of analogous forms.  A song ==> piano, guitar, etc.  A sphere ==> gold, steel, etc.  We teach abstraction by presenting a set of different things (physical or conceptual) and pointing out the common features that called formal properties.  formal properties are those properties that allow us to express the form of a thing.

L4-S7 Modeling Concepts 2003 SJSU -- CmpE M.E. Fayad 7 Concept  “A concept” is an abstract form or an abstraction.  There is a set corresponding to each concept.  “The dress is white” means the dress is a member of the set of white things.  These sets need not to be disjoint (i.e., the same member may appear in several sets.  The white dress is short and charming.  These set are called classes or categories.  Concepts are formal properties we use to describe things.  The primitive notions of a factual scientific theory are its concepts  Biology ==> cells, bacteria, virus, animal, plant, etc.  Adjectives & adverbs usually are the names of concepts in English

L4-S8 Modeling Concepts 2003 SJSU -- CmpE M.E. Fayad 8 Roles  A “role” is the part of a person or thing plays in a specific situation, operation, etc..  Many different object can play the same role.  Many roles can be played by the same object.  The white dress is short and charming.  A description of a role involves descriptions of:  Activities to be performed  Sequences or processes  Commands to be given and received  Roles are, therefore, abstractions (i.e., abstract forms or concepts).  In fact, roles are abstract temporal forms (i.e., a certain behavior at relative points in time).

L4-S9 Modeling Concepts 2003 SJSU -- CmpE M.E. Fayad 9 Actors  Roles are defined independently of the things used to play that role.  Conversely, Actors are classes that are capable of playing different roles.  They are often classes of physical things.  Man, Woman, Car, etc.  They are often capable of playing different roles in the same time  Woman ==> Doctor, Mother, Pilot  They often take-on and lose roles over time

L4-S10 Modeling Concepts 2003 SJSU -- CmpE M.E. Fayad 10 Discussion Questions Define: logical forms, abstraction, concepts, roles, actors, and objects T/F Logical forms are classes. Concepts are attributes. Structures are inheritance. Abstraction is the consideration of a form apart from its contents. Debate: Roles are important than actors in any software development. What are the differences between actors and roles?

L4-S11 Modeling Concepts 2003 SJSU -- CmpE M.E. Fayad –Object-Oriented Concepts Classes Objects Attributes Methods Messages Associations Aggregations Inheritance Polymorphism Localization 11 Questions for the Next Lecture

L4-S12 Modeling Concepts 2003 SJSU -- CmpE M.E. Fayad 12 Tasks for Next Lecture Task 1: Problem Statement for team projects are needed (see sample problems on OOPSLA – DesignFest). This is due on the third week of the semester. Task 2: Identify the team members of your team. Select a team name and me, the team name, team’s members’ names, their s, phone numbers -- Immediately. Task 3: Think about extra assignments and writing essays. me if you like to start right away. Please note that problem statements must be submitted electronically as MS Word format.