Solving Programming Problems in Intelligent Programming Tutors for Teaching the ObjectOriented Progr

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Solving Programming Problems in Intelligent
Programming Tutors for Teaching the
Object-Oriented Programming Paradigm

• Nelishia Pillay
• School of Geological and Computer Sciences
• University of Natal Durban, KwaZulu Natal,
  South Africa

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Introduction

• Problems experienced by novice programmers.
• Intelligent Tutoring Systems
• PROUST (Johnson et. al. 1990)
• Molehill (Singley et. al. 1991)
• The Lisp Tutor ( Anderson et. al. 1985)
• Pascal Loop Tutor (Wood et. al. 1996)
• Intellitutor (Ueno 1991)
• High developmental costs (Suthers 1996 and Murray
  1996)

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Proposed Generic Architecture

• Surveys were conducted to determine
• The facilities that should be provided by an
  intelligent programming tutor.
• The shortcomings of existing programming tutors
  in order to ensure that these shortcomings are
  not replicated in the generic architecture.
• The domain is restricted to hybrid
  object-oriented languages which combine the
  procedural and object-oriented programming
  paradigms.
• Topics covered object-oriented design, single
  inheritance, composition, abstract and concrete
  methods and polymorphism.

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Overview of the Proposed Architecture
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Types of Programming Problems

• Debugging of learner programs (Du Boulay 1988)
• Inducing solutions to programming problems.
• Solve a programming problem by reusing existing
  classes (Singley et. al. 1991). The Expert Module
  must be capable of choosing suitable components
  from the Domain Module for reuse.

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Solving Object-Oriented Programming Problems

• Object-oriented design.
• Developing algorithms for each method.
• Developing algorithms for the driver program.
• Convert the algorithms to a particular
  programming language.

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Knowledge Required

• The characteristics of entities in a domain and
  the relationships between the entities.
• Methods that are applied to entities in the
  domain.
• The tasks that must be performed by the program
  as specified in the question of the programming
  problem.
• If a driver program is required the goal/s of the
  program is/are specified as a set of input and
  corresponding output states.

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Input

• Question
• Object-oriented design Includes an inheritance
  hierarchy and induced algorithms.
• Object-oriented design and driver program.
• Application Domain
• Entity Attributes, procedures which take the
  entity as input or output.
• Procedure Destination, source, and test cases .

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ExampleEntities

• Bank Account Example Adapted from Problem
  Solving with C, The Object of Programming W.
  Savitch, 1999.

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Example Procedures
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Output

• A listing containing all the classes and abstract
  classes and their corresponding attributes and
  procedures.
• An inheritance hierarchy.
• An algorithm for each method and driver program
  (if applicable) in the form of a parse tree.

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Example Algorithms
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Object-Oriented Design

• The crux of object-oriented programming is
  object-oriented design (Barr , 1999).
• This process involves determining the different
  classes, the relationship between classes and
  identifies aggregate, abstract and concrete
  classes (Harmon et. al. 1999 Winder et. al.,
  2000).
• The Class, Responsibility and Collaboration
  method vs. the Searching and Requirements
  method (Winder et. al. , 2000).

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The Knowledge Base and Object-Oriented Design

• Conceptual graphs are used to represent the
  application domain and program goal/s.
• Three data dictionaries the entity, type and
  procedure dictionary are maintained.
• The projection matching procedure defined by Sowa
  (1984) is used to generate the inheritance
  hierarchy.
• An extraction process is applied to the graphs
  to determine super classes and abstract super
  classes.

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Algorithm Induction

• Genetic programming (Koza, 1992) is used for the
  purposes of algorithm induction.
• Overall Algorithm
• Create an initial population.
• Repeat
• Evaluate each individual in the population.
• Select individuals to apply the genetic
  operators to.
• Create new individuals by application of the
  genetic operators.
• Until the termination criterion has been met.

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Discussion and Future Work

• Structured Programs
• Parsimonious programs
• Modular programs
• Problem types
• Authoring components
• Converting algorithms to a particular language.
• Object-oriented languages