The AlgoViz Project

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The AlgoViz Project

• Cliff Shaffer
• Department of Computer Science
• Virginia Tech
• Blacksburg, VA

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AVs The Problem (1)

• Some identifiable successes for AVs
• Lots of no significant difference results
• But some AVs have been shown to be pedagogically
  effective
• Steady progress is being made in understanding
  how to design and use AVs

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AVs The Problem (2)

• AVs have high faculty and student favorability
  ratings
• But AVs have little overall impact on education

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AV Community (AlgoViz)

• http//algoviz.org/
• Solution
• Build a community of users/developers
• Better disseminate best practices information
• NSF CCLI grant, connections to NSDL/Ensemble
  project

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AlgoViz Wiki Catalog Data

• A collection of links to nearly 450 AVs
  http//algoviz.cs.vt.edu/AlgovizWiki/Catalog
• The collection allows us to do some analysis
• Topical Distribution
• (sorting gt30, linear structures gt10)
• Who/where (60 by teams/major projects)
• Quality (68/207/113)
• Access Stability (a lot of URL churn, a few get
  lost)

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Next Step NSDL Project Proposal

• Create a new model of dissemination to lower
  barriers to access
• Move away from the digital library model of
  users coming to collections
• Notification via social networks
• Focus on community-driven content development
• Discussion, review, ratings
• Think Amazon, but we have critical mass issues

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OpenAlgViz

• SourceForge Project
• Collect and host AV software
• Exemplar AVs
• Software libraries for AV developers
• Software infrastructure

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Algorithm Visualization Features

• Study the details of AV implementation in an
  effort to understand how to best design AVs
• Pseudocode display
• Back Button
• Example (test) data vs. students entering tests
• Animation vs. next step

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Tutorials vs. AVs

• Integrated text and activities (applets)
• Guide questions/directed activity
• Built-in quizzing (future)
• Explanatory applets vs. analysis applets
• Takes a long time to develop (several students
  over two-three years)
• In progress (at VT)
• Hashing
• Memory management
• Search Trees

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AVs Hashing Tutorial

• Section 1 Standard lecture and textbook for one
  week
• Section 2 In-class tutorial use for one week
  (same material)
• Student reaction Universally positive for
  tutorial
• Section 2 had significantly better score in
  post-test