1. Pad++: A Zooming Graphical Interface for Exploring Alternate Interface Physics Benjamin B. Bederson and James D. Hollan Presented by Daniel Schulman

2. What is Pad++? A system for building interfaces based on 2.5-D zooming. Implemented in Tcl/Tk and C++. “Semantic Zooming” – more info is shown when zoomed in.

3. Motivation View large amounts of information w/out having to hide some. Provides structure to data, to complement “filter” approaches. Avoid limitations of metaphors. (“dead metaphors”).

4. Application - Hypertext When linked data is clicked, it is displayed in the same “space”, but smaller and to the side. Visual representation of browsing history.

5. Application – Directory Browser Files are shown “inside” directories. More details (files in directories, file sizes, etc.) become visible as you zoom in.

6. Critique Introduced lots of important ideas that are now major research topics. Proof-of-concept for zooming interfaces. No direct attempt to evaluate success of approach. Need to discuss pros and cons of “physics- based design” more.

7. Physics-Based Design + More abstract metaphor. + Less real-world limitations. + Scales to larger information sets. - Some have poor spatial reasoning. - Manipulation is more complicated. - “Easily discoverable”? - Lack of affordances.

8. Future Work Real user evaluation. Different kinds of physics. Manipulation of objects, not just viewing. Affordances for alternate physics. Navigation of large virtual spaces.