Carnegie Mellon University

GridCity Programming

An Introduction to Programming (in Java)

• Examples
• Overview
• Download GridCity
• Help (HowToUse, Frequently Asked Questions, Javadoc, Changing images)
• Courses
• Brought to you by (ActiveTutors Project, People)

Welcome

GridCity is an add-on to Java that allows new programmers to write Java programs that control vehicles in a graphical world. Programs typically instruct vehicles to move around as well as to pickup and deliver parcels. Powerful feats can be accomplished in such programs such as searching and sorting (see examples). Also, different programming paradigms can be explored such as stepwise refinement and object-oriented programming. Below is an example of a GridCity program in operation. Click on the run button and the vehicles will arrange parcels to spell hi. (See more examples)

Streets
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4
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	0	1	2	3	4	5	6	7	8	Avenues

GridCity Advantage

A primary advantage of this approach is that programmed actions are visible on the screen during operation. Errors in intent (such as a vehicle moving in the wrong direction) and errors in execution (such as a vehicle crashing into a wall) can be easily seen. This approach is in sharp contrast to traditional programming where programmed actions take place inside the computer and are not easily visible. (See comparison of related programming environments for Pascal, C and C++).

Using the GridCity programming environment, students can be gradually introduced to algorithmic thinking within a Java programming environment. As a result, GridCity can be used as a preliminary introduction at the beginning of a programming course; or alternatively, GridCity can be used alone as an introductory course on solving problems by programming. Contents of such a course could include: program format, types of errors, grouping instructions, conditionals, loops, recursion, classes, methods, inheritance, threads and algorithmic thinking. (See on-line course, see on-line tutor)

Example Programs

• 90-775 Java Programming course
• GridCity Share Library

Related Courses

• 90-775 Java Programming course
• ActiveTutors: Java

• Jennifer Crawford
• K. C. Marshall
• Maria Stidle
• Latanya Sweeney

• ActiveTutor: Java
• Power Learning C++
• ActiveTutors pedagogy
• Courses: Tutor-based or Lecture-based
• Publications

Related links at (CMU)

• H. John Heinz III School of Public Policy
• Center for Automated Learning and Discovery
• School of Computer Science
• Advanced Computer Tutoring (ACT)
• Project LISTEN

Brought to you by

H. John Heinz III School of Public Policy
at Carnegie Mellon University (CMU)

Principal Investigator: Latanya Sweeney, Ph.D.

Contact Information

• Address: ActiveTutors Project, Carnegie Mellon University,
  1301 Wean Hall, Pittsburgh, PA 15213 USA
• Telephone: Sherice Livingston
• Email: tutors@dataprivacylab.org