This document discusses using the Logo programming language and MSWLogo software to teach computer science concepts through constructivist educational techniques. It provides an overview of Logo's history and basics, describes how to teach iteration through getting a turtle to draw a square, and teaches recursion by having students write a program to draw a fractal fern pattern. Examples of Logo code are given to illustrate programming concepts hands-on through turtle graphics. The goal is to make programming fun and creative for students by engaging them in exploration and knowledge construction.

1. Powerful Ideas
Constructivist Educational
Techniques in Computer
Programming Using MSWLogo©
Copyright 2002, Tony Gauvin, UMFK

2. Introduction
 Tony Gauvin, Assistant Professor of E-
Commerce, UMFK
 Developed an Interest in MSWLogo as a tool
for exploration of advanced Computer
Science Topics while a Graduate Student at
UM
 Based on Draft copy of Discrete Logo written
by Dr. George Markowsky, Chair, Computer
Science Department, UM

3. What Is Logo?
 Logo is both an educational Philosophy and a
programming language based on
Constructivism
 Constructivism views knowledge as being
created by learners in their own minds
through interaction with other people and the
world around them.
 This theory is most closely associated with
Jean Piaget, the Swiss psychologist, who
spent decades studying and documenting the
learning processes of young children.

4. A Brief History of Logo
 Seymour Papert and Marvin Minsky
co-founded MIT’s Artificial
Intelligence Lab in mid ’60s
 Papert and others developed the
Logo programming language in 1967
 In 1980 Papert published
Mindstorms

5. Logo Basics
 Turtle(s) moving in a world controlled by
the user
 Turtle(s) act on and react to the World
controlled by the User
 The only data structure is a list (LISP
heritage)
 Commands are simple and intuitive
 “low threshold and NO ceiling”

6. LOGO Today
 STARLogo
 Massively Parallel
 Developed by Mitchel Resnick at MIT
 Turtles, Termites, and Traffic Jams:
Explorations in Massively Parallel Microworlds
 UCBLogo
 Unix, msDos, Mac
 Brian Harvey at UC at Berkeley
 Computer Science Logo Style

7. LOGO Today
 MSWLogo
 Windows (GUI) version of UCBLogo
 George Mills at Softronics, INC
 Has all the power of any windows
programming Language
 Great tool for exploring Advanced
Computer Topics

8. Today’s Topic
 Teaching programming concepts using
MSWLogo
 Two goals
 Use Iteration in Geometric Constructions
 Use Recursion In Geometric Constructions

Fractals
 Methods of Instruction
 The student experience is Totally Hands On
 By using Constructivism Educational Philosophy

9. MSWLogo Primer

10. Turtle commands
 To move
 Forward (# of steps) FD
 Back (# of steps) BK
 Home (back to the Middle)
 To Turn
 Right (# of Degrees) RT
 Left (# of Degrees) LT
 Pen Commands
 PenUp PU
 PenDown PD
 SetPenColor [Red, Green, Blue] O-255

11. MSWLogo Commands
 Edit <procedure>

Creates a procedure (program)
 Edall

Edit all procedures in memory
 ClearScreen CS
 Repeat # [stuff to do]
 :<Identifier>

Variable (place to store stuff .. Memory)
 Mathematics

*, +, -, /

(4 +3)/12*3-6

12. Draw a square
 Lets make the turtle draw a square
 First think how you would draw a square.
 Then tell the turtle to do it
 FD 100 RT 90
 FD 100 RT 90
 FD 100 RT 90
 FD 100 RT 90
 Repeat 4 [FD 100 RT 90]

13. Create a program for Drawing
a square
 Invoke the editor by typing “edall”
 Every procedure
To <name> <maybe some stuff>
<stuff to do>
End
 Remember variables can be used (:X)

14. The square program
To square : size
Repeat 4 [fd :size rt 90]
END
Type run square #

15. Something Cool
 What if the turtle took a step and turned
slightly and drew another Square?
 And then did this a bunch of times??
 To cool :size
Repeat 100 [square :size fd 1 rt 10]
END

16. Something Cool

17. Drawing a fern
 A fern is a Fractal
 Structure is repeated
 Every leaf is a fern
 Structure is recursive

18. MSWLogo Fern
 A Fern is
 A stem
 A fern to the left
 A fern to the right
 A fern to the front

19. Program for Drawing a Fern
 Teaching a turtle Botany
 Fern program
 Go forward
 Draw a fern to the left
 Go back
 Draw a fern to the right
 Go Back
 Draw a fern to the front
 Go Back
 Till it gets too small to draw

20. The program
to fern :size
if :size < 4 [stop]
fd :size / 25
lt 90 fern :size * .3
rt 90
rt 90 fern :size * .3
lt 90 fern :size * .85
bk :size / 25
end

21. A Cool Fractal Fern

22. What we learned
 Programming using Iteration
 Turtle drawing Square
 Programming using recursion
 Turtle drawing Fractals
 Programming is fun AND creative

23. Logo Resources
 MSWLogo
 http://www.softronix.com/logo.html
 Logo Foundation
 http://el.www.media.mit.edu/groups/logo-
foundation/
 Logo Art Gallery
 http://www.geocities.com/CollegePark/Lab/2276/
 Beginnings of My Logo workshop
 http://littleblack.umfk.maine.edu

24. Questions??