Managing diversity in introductory programming classes

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Managing diversity in introductory programming
classes

• Using Logo as a diagnostic tool
• John Poulton
• North East Wales Institute

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Introduction to Programming

• The one module in our Level 1 curriculum that the
  students
• have the most difficulty
• complain about the most consistently
• a "weed out" class where only the highly
  successful will endure
• a "make or break" course which discourages all
  but the best students

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BSc Computing

• 2000/2001
• 44 failure (withdrawals, fail/referrals)
• 56 success !
• 35 transferred to BIT / MMC
• 36 progression
• 112,000 in lost revenues

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Student Qualifications - 2000/01
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Student Age - 2000/01
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The root of the problem

• wide range of backgrounds and aptitudes
• wide range of programming backgrounds and
  aptitudes
• makes the class boring for some and too
  challenging for others
• To fix this imbalance
• set classes !
• needed to identify members of the class prior to
  starting the module
• who may potentially need extra help
• who would benefit from further challenge

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Diagnostic Tool

• Aptitude Tests
• Test programming skills
• what can they do?
• what cant they do?
• what can we do?
• What language?

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Choosing a tool

• Introduce them not to the language itself, but to
  programming itself.
• We want to introduce them to the exciting ability
  to make the computer do as we want
• Not overwhelm them with details of a specific
  implementation

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Hello World

• The most important thing to realise about
  non-programmers
• they are not programmers
• Every programmer is familiar with "Hello, World!"
  
• The traditional first program when learning a new
  language
• Examining this simple program is a good way to
  learn useful things about how we should teach new
  students who have never written a program before

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C "Hello, World!"

• include ltiostreamgt
• int main(int argc, char argv)
• cout ltlt "Hello, World!\n"
• return 0
• This is an overwhelming amount of information for
  the new programmer to deal with, when the goal is
  simply to "make the computer print something

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Java "Hello, World!"

• public class HelloWorld
• public static void main(String args)
• System.out.println("Hello, World!")
• the OO bit just adds an additional level of
  complexity

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C and Java

• "Don't worry about that, we'll learn what it
  means later."
• How is this a useful approach to imparting
  knowledge and teaching students?
• Both these examples are compiled languages
• This means that we must teach the student how to
  use a compiler before they even see the output of
  their program

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Computer v Compilers

• Students often have little understanding of the
  underlying operations of a computer and the
  compiler.
• Have difficulty conceptualising how the computer,
  the language, and the compiler interact
• Students' incomplete or faulty mental models of a
  computer and programming syntax and semantics
  cause problems

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Computer v Students

• Students tend to anthropomorphise the computer
• Often they assume a computer will understand
  their incomplete or faulty commands and execute
  them as they understand them, not the way the
  computer is designed to execute them.

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Compiled v Interpreted

• So what is a better language for new programmers?
• Guido van Rossum's Computer Programming For
  Everybody suggests the interpreted language Python

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Python "Hello, World!"

• print "Hello, World!
• However
• gtgtgt print fred 7
• Traceback (innermost last)
• File "", line 1, in ?
• TypeError illegal argument type for built-in
  operation

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Logo?

• Full-featured computer programming language
  derived from LISP
• A language for learning
• A tool to teach the process of learning and
  thinking
• An environment where students assume the role of
  teacher

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Logo

• As a teacher, they must
• understand the knowledge to be taught
• plan an approach to impart this knowledge
• break the knowledge into small, understandable
  chunks clearly communicate the knowledge
• Establish this new knowledge as the foundation
  for future learning
• Be aware of and build on knowledge that the
  learner already has
• Respond to the learner's (computer's)
  misunderstandings and errors

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How did we use Logo

• As an introduction to the concept of programming,
  and on the thinking processes that Logo
  encourages
• To attempt to discover programming aptitude
• Used during induction week
• 65 BSc , 37 HND students (2001/02)
• BSc 3 hrs 1 hr test
• HND 4 hrs 1 hr test

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How did we use Logo

• Developed tutorial and series of exercises
• Simple tasks which require fairly short
  programming solutions
• Encouraged the use of various language constructs
• Loops
• functions
• parameter passing
• The tasks examined attention to detail, logical
  ability and capability at comprehending and
  following instructions

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Sequences

• forward 50 right 90 forward 50right
  90forward 50right 90forward 50right 90

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Iteration

• repeat 4 forward 50 right 90

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Procedures

• to squarerepeat 4 forward 50 right 90end

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Procedures

• You could draw a flag
• forward 60squareback 60

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Further Iteration

• You could make a circle of squaresrepeat
  12square right 30

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Procedures

• to house square forward 50 right
  90 triangleend
• to trianglerepeat 3 forward 50 left 120end

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Passing Values into Procedures

• to square sizerepeat 4 forward size right
  90end
• square 10
• square 20 etc

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Recursion

• to design clearscreen right 30 polyspi 5
  120end
• to polyspi size angleif size gt 205
  stop forward size right angle polyspi
  size5 angle.12end

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Results
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Results

• Results were used to enable setting of groups
  after discussion with students
• BSc 4 groups of approx 16 students
• Top 2 3hrs contact 1 lecture 2hrs lab /
  extension
• Bottom 2 4hrs 1 lecture 2 lab 1 tutorial/repeat
  lecture
• HND 2 groups of approx 18
• 4hrs 1 lecture 2 lab 1 tutorial/extension
• 4hrs 1 lecture 2 lab 1 tutorial/repeat lecture
• Progress monitored with personal tutors
• Target extra support at weaker students
• one to one sessions

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BSc Computing

• 2001/2002
• 36 failure (withdrawals, fail/referrals)
• 64 success !
• 18 transferred to BIT / MMC
• 52 progression
• 92,000 in lost revenues
• 2002/03 (on going)
• 30 failure (withdrawals, fail/referrals)

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Conclusions

• Logo
• Useful diagnostic tool
• Useful tool for teaching programming
• Useful tool to observe how students think
• Improved retention progression?
• Helped
• But so did extra tutorial support
• Future work
• develop materials further
• Introduce problem solving module utilising LOGO

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Logo sites

• MSWLogo is available free from
• http//softronix.com
• Useful Site run by the Computer Supported
  Didactics Working Group at the University of
  Vienna
• http//www.eurologo.org/
• Guido van Rossum's Computer Programming For
  Everybody
• http//www.python.org/doc/essays/cp4e.html