Data Structure Visualization Vikrant Colaso Kunal Garach Anuj

Data Structure Visualization Vikrant Colaso Kunal Garach Anuj Shah

Why use animation for visualizing Data Structures? • Instead of students mentally running the algorithm, the animation helps rapid perception of the data structures. • They can also dynamically portray the changes in data structures as the algorithm evolves. • User can control speed of execution and thus learn at his own pace.

Previous Work Numerous attempts have been made to prove that Visualization helps in learning. Our Study Testing Retention of Information Gained using Different Media. (Animation, Standard Text and Both)

Tool Used

Tests Phase 1 • Students from CS 2604 were given a time limit of 20 minutes to learn both DFS and BFS using either the text, tool or both. • A 10 minute, multiple choice test was taken at the end to evaluate their understanding of procedural as well as conceptual aspects of the algorithms. Phase 2 • After a period of 15 days a second test was conducted to test the retention. Tests were designed using HTML and Java. Script in order to record the time taken on each question.

Data Collected Demographic Survey: Name, GPA, Prior knowledge of Graph and Graph searching techniques. Post Test Questionnaire: Understanding of algorithms, prediction of score, helpfulness of presented material, comments on the material. Tests: Time taken on each question, total scored on each category of questions.

Data Analysis • Using Spotfire and Excel. • ANOVA, T- tests.

Results 82% confident that there is a significant difference between T+T and Text Average scores for the Text Group is the least.

Results Contd…. Decrease in Average Scores

Results Contd…. Better 79. 83% confident that there is a difference in average scores for the second test This indicates a trend that degradation for the Text group is the most.

Results Contd…. Better 61. 50% confident that there is a difference in average procedural scores for the second test This indicates a trend that degradation for plain text is the most.

Results Contd…. 99. 88% confident that the Text + Tool combination is rated as the most helpful.

Results Contd…. 88. 62% confident that the average GPA on Text+Tool was less than that on Text

Is this relevant? 91. 68% confidence that the average time taken on conceptual questions is less for tool.

Summary of Trends in data • A poor average score for those who used the text on the 2 nd test. • A poorer average score on procedural questions as well for those using the text. • The textual material was the least appreciated. • GPAs of students on the text were on an average higher than those using both the text and the tool.

Conclusions General Comments: • Almost all the students liked the Tool and felt that it was a novel method for teaching. • Those who got the Text felt they may have done better with a graphical visualization of the data structures. • Remembering the algorithms was difficult for almost all the students however those using the tool could remember some of the steps.

Further Work Recommend that students be given a longer time/Assignments with the tool to notice a trend. Recommend testing with review of material before taking the second test. Recommend using a tool with speed control, history and other enhancements. Studies should be conducted with a larger number of students and questions.