Metaphor-Based Animation of OO Programs

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Metaphor-Based Animation of OO Programs

• Jorma Sajaniemi, Pauli Byckling, Petri Gerdt
• University of Joensuu, Finland
• SOFTVIS 06, Brighton, U.K.

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Outline

• Motivation
• Metaphors for Object-Oriented Concepts
• Demo
• Typical Novice Misconceptions
• Conclusion

3
Motivation

• Existing OO visualization systems are based on
  programming language implementation or UML
• novices lack implementation knowledge
• novices lack UML knowledge
• Metaphor the presentation of a new idea in terms
  of a more familiar one
• similarities and dissimilarities enhance active
  learning
• We present
• novice-level metaphors for OO concepts
• animation that uses these metaphors

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Metaphors for OO Concepts

• Classes blueprints in a blueprint book

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Metaphors for OO Concepts

• Classes blueprints in a blueprint book
• Objects watch panels
• State monitors
• Member variables role metaphors

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Metaphors for OO Concepts

• Classes blueprints in a blueprint book
• Objects watch panels
• State monitors
• Member variables role metaphors
• Method invocation workshops
• Static methods (main) permanent workshops

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Metaphors for OO Concepts

• Classes blueprints in a blueprint book
• Objects watch panels
• State monitors
• Member variables role metaphors
• Method invocation workshops
• Static methods (main) permanent workshops
• Message passing envelope

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Metaphors for OO Concepts

• Classes blueprints in a blueprint book
• Objects watch panels
• State monitors
• Member variables role metaphors
• Method invocation workshops
• Static methods (main) permanent workshops
• Message passing envelope
• Return values workbench

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Metaphors for OO Concepts

• Classes blueprints in a blueprint book
• Objects watch panels
• State monitors
• Member variables role metaphors
• Method invocation workshops
• Static methods (main) permanent workshops
• Message passing envelope
• Return values workbench
• Object reference pennants

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Metaphors for OO Concepts

• Classes blueprints in a blueprint book
• Objects watch panels
• State monitors
• Member variables role metaphors
• Method invocation workshops
• Static methods (main) permanent workshops
• Message passing envelope
• Return values workbench
• Object reference pennants
• Garbage collection garbage vehicle

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Metaphors for OO Concepts

• Classes blueprints in a blueprint book
• Objects watch panels
• State monitors
• Member variables role metaphors
• Method invocation workshops
• Static methods (main) permanent workshops
• Message passing envelope
• Return values workbench
• Object reference pennants
• Garbage collection garbage vehicle

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Demo

• The demo animation is intended for novices
• First example of a simple OO program
• Novices are supposed to have be familiar with the
  PlanAni program animator, so they know the role
  metaphors
• The demo is intentionally faster than in novice
  use due to time constraints of this presentation

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Demonstration
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Typical Novice Misconceptions
Misconception Solution Parallellism hig
hlighted line Parameter passing value vs.
reference envelope, pennants Main program is
class permanent workshop Object is a piece of
program code blueprints, monitors Object is
class blueprints, watch panel Object is
variable monitors, role images Object is a
simple data store only workshops Only one
variable can refer an object pennants Work in
methods is made by assignment only workshop
animation Terminology (class, object, method,
...) metaphors (Eckerdal al.,
2005 Holland al., 1997 1986 Vainio, 2006)
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Conclusion

• Novices have a hard time comprehending OO
  visualizations that are based on unfamiliar
  concepts
• We have presented metaphors for novice-level OO
  program visualization
• OO metaphors may help to prevent typical novice
  misconceptions
• We plan to make a few, carefully selected
  animations for classroom use