1. Using Visual Logic To Teach A First Course In Programming Logic
Jorge Vallejos – Assistant Professor
Computer Science Department
Columbus State Community College
Ohio Educational Technology Conference - January 2014

2. Logic – AND Benefits to our students
What Is Logic ? – Loose Definitions :
The application of principles of correct reasoning
Proper thinking about the understanding of something
Interrelation of facts and events to reach valid conclusions
Why Is Logic Necessary?:
Solve complex tasks by applying systematic reasoning
Establish an approach to analyze and understand a problem
Discover simple and efficient solutions to implement processes and systems
What Do Students Gain By Learning Logic?:
Develop skills for critical thinking
Gather relevant facts, analyze them, and derive conclusions to troubleshoot systems
Apply problem solving strategies – formalize theories, discard invalid assumptions, establish priorities (ordering of actions and validation), solve problem in incremental steps, isolate/reproduce issues, test solutions
Readiness for programming courses and other analytical courses
Ohio Educational Technology Conference - January 2014

3. courses THAT support PROGRAMMING logic
MATH courses – beyond the algorithms and formulas, MATH creates the foundation to discover relations between entities, combine building blocks to compose new entities, build sets of detailed instructions to complete a task
READING /WRITING courses focused on comprehension – analyze complex materials, apply critical analysis to reach conclusions, inductions and deductions
PHYLOSOPHY courses: cover topics like: critical thinking, methods of inductive, deductive and symbolic logic.
Ohio Educational Technology Conference - January 2014

4. Tools for a First course in programming logic
Visual Logic
Creates visual representation of algorithms in flowchart format. The program does not use formal programming-language instructions – like Java, C#, or other programming languages
Alice/Alice3 – by Carnegie-Mellon
Creates 3D animations. Tool is oriented towards learning computer programming. Drag objects from a palette onto a scene canvas. Objects are constructed from Java classes. Methods are presented as menus – to control the actions performed by objects
Scratch – by MIT
Create animated objects. The program uses a list of instructions to control the actions performed by objects
Others – search the Internet
Ohio Educational Technology Conference - January 2014

5. Visual logic Features
Variables: non-typed numeric and string constants
There is no variable declaration – variables are created at the point of use
Constructs:
Assignments
Operators
Arithmetic (+, -, *, /, Mod, ^), Comparison (<, >, …), Compound (AND, OR, …)
Sequences
Conditions: if-then-else
Loops
while, do-while, for – control of execution can be modified by the exit, continue clauses
Arrays
Procedures (a.k.a., modules): named set of instructions.
Parameters: passed by value, passed by reference
Do not return a value
Ohio Educational Technology Conference - January 2014

6. Visual logic Features - Continued
Functions
FormatCurrency(), FormatPercent(), Round(), Random(), …
There is no Wait()/Sleep()-equivalent function. Alternative: use a busy-do- nothing loop
Input/Output
Dialog boxes, Console, File
Enforces Structured Programming – There is no GOTO instruction
All programming structures have a single entry/exit point
It is not possible to create spaghetti-code
Ohio Educational Technology Conference - January 2014

7. Visual logic PITFALLS
Variables are created at the point of use. When a variable identifier is misspelled, Visual Logic creates a new variable
Example:
Correctly spelled variable identifier: firstName.
Misspelled variable identifier: fisrtName – Visual Logic creates the new variable identifier with a default zero (0) value
Visual Logic does not enforce syntax – (justification: students learn logic better when focusing on the concepts – rather than syntax)
It is possible to create an invalid comparison in comparison/loop statements:
while (YES <> number) { … }, where YES stores the string constant “y”, and number is a numeric constant.
The comparison evaluates as false – no syntax error, the loop does not execute
An existing string variable can afterwards be assigned a numeric value
Ohio Educational Technology Conference - January 2014

8. VISUAL LOGIC DEMONSTRATIONS
Sequences
Decisions
Loops
Arrays
Parameterized Procedures
Graphics
Ohio Educational Technology Conference - January 2014

9. References Visual Logic http://www.visuallogic.org/
A Guide to Working with Visual Logic. Thad Crews & Chip Murphy. Course Technology – Cengage Learning. ISBN
Alice
Scratch
Ohio Educational Technology Conference - January 2014