LOGO CECS 4100 R. Christensen

What is LOGO? LOGO is a modern, procedural programming language based on the artificial intelligence language LISP. Although appropriate for beginners, it is a highly sophisticated language.

What is LOGO? LOGO is a procedural language. LOGO is an interactive language. The programmer receives immediate feedback. LOGO has turtle graphics. LOGO uses lists as data objects. Numbers, characters, and words can be manipulated in LOGO. Lists are compound data structures.

LOGO’s Philosophy for Computer Use in the Classroom Seymour Papert is the Father of LOGO. His theoretical background comes from the area of artificial intelligence and from the work of Jean Piaget. Papert believes the computer is best used in education as an “object to think with” rather than a dispenser of information.

What is a MicroWorld? The concept of “microworld” is one Papert used to describe LOGO and LOGO-like environments. An environment for learning in which children are free to experiment, test, and revise theories, and invent their own activities.

Versions of LOGO Original microcomputer versions were available in 1979 for the TI 99/4 home computer and the Apple II computer. LCSI LOGO is what we are using Available for IBM and Apple Terrapin LOGO for Apple II family LOGOWriter (LCSI) combines LOGO and word processing

Why Use LOGO? Provides a sound introduction to programming but is more than a programming language Encourages thinking and problem-solving skills applicable across the curriculum Debugging Learning from errors - immediate feedback Creates an ideal environment for experimenting and learning hypothesis-testing skills

Research on LOGO May facilitate achievement gains in the area of mathematics May facilitate problem-solving ability Evidence indicates that LOGO can serve as a powerful tool in encouraging prosocial interaction, positive self-image, positive attitudes toward learning. In general, evidence suggests that working in pairs is most advantageous for LOGO

Programming in LOGO The Primitives commands LOGO “knows” FD (forward) BK (backward) RT (right) LT (left) HOME (goes to home position) PU (lifts the pen) PD (puts the pen down)

Programming in LOGO Perspective - sitting on the turtle’s back Procedures Teaching the turtle new tricks TO SQUARE REPEAT 4[FD 50 RT 90] END Procedures are called from the main program

Programming in LOGO Using LOGO variables Allows an assigned value to a variable so the procedure can be used multiple times with different values TO SQUARE:SIDE REPEAT 4[FD :SIDE RT 90] END Square is the procedure, side is the variable so the square procedure can be used for multiple sizes of squares

Programming in LOGO What would happen here? TO SQUARE REPEAT 4[FD 50 RT 90] SQUARE END

Programming in LOGO Recursion is an endless loop Can be stopped if a conditional statement is used IF :SIDE > 100 STOP TO SPIRAL :SIDE IF :SIDE>100 STOP SQUARE :SIDE RT 10 SPIRAL :SIDE+5 END

Programming in LOGO LOGO numbers, words and lists LOGO “knows” how to add, subtract, multiply and divide (+,-,*,/) The command PRINT (3+5)/2*8 will output 32 To indicate the data-type word, type a quotation mark in front of the string PRINT “Happy Birthday Output Happy Birthday

Programming in LOGO LOGO Lists A list is a group of words indicated by brackets PRINT [TODAY IS TUESDAY] Output TODAY IS TUESDAY Can teach the computer “how to talk”, how to create sentences and how to write poetry

Programming in LOGO LOGO Music Command is TONE followed by 2 inputs - one is frequency (pitch) and the second is duration TONE 300 60 Procedure for music might be TO SONG TONE 252 56 TONE 349 56 TONE 365 56 END

Programming in LOGO Using music in procedures and subprocedures TO MUSIC REPEAT 5 FIRST where first is the name of the first part of the song SECOND second is the name of the second part of the song THIRD third is the name of the third part of the song END