Nov 2002C.Watters 1 But I’m on my PDA! Device Independence Carolyn Watters Web Information Filtering Lab Faculty of Computer Science Dalhousie University

Nov 2002 C.Watters 2 Overview Big Plan Use features Transformations Collaborations What next

Nov 2002 C.Watters 3

Nov 2002 C.Watters 4 Scenarios Full Web access on range of devices Migration between devices mid-task Collaboration including mixed devices

Nov 2002 C.Watters 5 General Picture

Nov 2002 C.Watters 6 The Problem Accessing data on a small screen is NOT the same as on a larger screen Same data for all users Device display and input get in the way!

Nov 2002 C.Watters 7 General Approach ElideTransform Syntactic Semantic Outlining Remove content Compress images Text summarization Retain Full Images Text/Tables/Forms Bickmore-Schilit Matrix

Nov 2002 C.Watters 8 Process

Nov 2002 C.Watters 9 Decomposition/Parsing HTML tag clues Frames Javascript + rules

Nov 2002 C.Watters 10 Display Composition Generate pages for display Maintain session state Maintain collaboration state

Nov 2002 C.Watters 11 Transformations Text Lists Tables Forms Images Links Scripts Applets Frames

Nov 2002 C.Watters 12 Use Features  In screens, size matters  Small screen is NOT just a small window on a large screen  Small screens do work  Scrolling minimized  Context preserved  Search added  Hierarchy used

Nov 2002 C.Watters 13 Text Transformations Chunk text to logical units Eliminate sideways scroll Keep clear context Add search

Nov 2002 C.Watters 14 Text

Nov 2002 C.Watters 15 Lists

Nov 2002 C.Watters 16 Forms

Nov 2002 C.Watters 17 Transformation

Nov 2002 C.Watters 18

Nov 2002 C.Watters 19 90% effective over 200 random sites with forms

Nov 2002 C.Watters 20 Problems Tables used as display structures Long segments Maps and images within form

Nov 2002 C.Watters 21 Tables & forms

Nov 2002 C.Watters 22 Tables  Using complete large tables on small devices  What is worth using screen space for?  Task Matters:  Simple look up task  More complicated task

Nov 2002 C.Watters 23 Tables

Nov 2002 C.Watters 24 Search only Context Search & Context Plain & search

Nov 2002 C.Watters 25 Measures  Effectiveness = % right answer for each task  Efficiency = number of clicks to get the correct answer NB: Not interested in time taken as a dependent variable

Nov 2002 C.Watters 26 Results:Effectiveness Both tasks did better on whole table For simple task --bigger screen performed better For complex task – no significant difference by size – adding context gave significant improvement search – wrong answers in complex task – worse as the screen got smaller [got to the wrong place faster or just wanted to use it ‘cause it was there!]

Nov 2002 C.Watters 27 Results Size matters for both efficiency and effectiveness Context is worth the space Search function is not necessarily helpful for complex task – Make it optional/toggable

Nov 2002 C.Watters 28 Collaboration Cross devices Between devices

Nov 2002 C.Watters 29 Collaborative sessions

Nov 2002 C.Watters 30 Session & Task Dependence

Nov 2002 C.Watters 31 Device Dependency

Nov 2002 C.Watters 32

Nov 2002 C.Watters 33

Nov 2002 C.Watters 34 Screen Collaboration Use multiple screens to provide larger view Other collaborators may be on larger screen OR smaller screens

Nov 2002 C.Watters 35 Collaboration potential

Nov 2002 C.Watters 36 Navigation Models Landmarks (bookmarks + post it notes) Overview maps (50,000 feet)

Nov 2002 C.Watters 37 Mapping Options tree sequence type DNA map

Nov 2002 C.Watters 38 Late Committal Navigation Do not click thru the hierarchy but go directly Extract enough info to decide Brush through hierarchy or list of segments Need to be able to present an overview (Focus + Context model)

Nov 2002 C.Watters 39 Brush Navigation

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Nov 2002 C.Watters 41

Nov 2002 C.Watters 42 Now What? User studies Development of use guidelines More on sessions More on tables Attention and inhibition characteristics

Nov 2002 C.Watters 43 Thank you!