1. Reading of Electronic Documents: The Usability of Linear, Fisheye, and Overview+Detail Interface by Kasper Hornbæk, Erik Frøkjær Presented by Luhui Hu on Apr 19, 2001

2. Motivation -why analyzes reading of electronic documents Electronic documents are increasingly being used Reading plays a central role in information access and use

3. Information visualization techniques -- used in reading of electronic documents Linear Interfaces –Notepad –Office Word Fisheye Interfaces –Document Lens –Flip Zooming Overview+detail Interfaces –Seesoft –Thumbar –PDF Acrobat Reader –Office Powerpoint

4. Examples -- Linear, Fisheye & Overview+Detail Interfaces Linear Fisheye Overview+Detail

5. Experiment Design --Comparing the usability of three interfaces for reading scientific documents Three kinds of interfaces –Linear, fisheye & overview+detail Subjects –20 CS graduate students Tasks –Essay (reading-to-learn-to-do) –Question-answer (reading-to-do) Six IEEE journal papers –2 tasks, 3 interfaces Usability Measures –Effectiveness –Satisfaction –Efficiency –Reading patterns

6. Usability(1)-Effectiveness Overview+Detail (O+D) gains the highest grade in each category (especial in essay tasks) Fisheye lies in the middle Notes: –4 points totally –O+D: Overview+Detail –Q-A: Question-answering –AG: Author’s Grading –SG: Subjects’ Grading

7. Usability(2)-Satisfaction Satisfaction Questions –How was the system to use? –How do you perceived the tasks just solved? –Were your answers to the tasks? –How much did you learn from reading the papers? –Were the papers just read? –Was information in the two papers just read? 95% prefers O+D 5% prefers Linear 0% prefers Fisheye

8. Usability(3)-Efficiency 1-Linear, 2-Fisheye, 3-Overview+Detail Essay tasks: –Fisheye is significantly the fastest (16% faster) –Linear & O+D are similar with each other Question-Answering Tasks –Linear is the fastest –Using O+D took 20% longer than using linear

9. Usability(4)-Reading Patterns 1-Linear, 2-Fisheye, 3-Overview+detail Fisheye needs more frequency to study Fisheye needs more time to have initial orientation Fisheye needs less time to review & read through

10. Conclusion Overview+detail: –best supports reading electronic documents –be strongly preferred by subjects (readers) –needs more time for answering questions Fisheye: –faster reading (time-critical) –less understanding Linear: –Inferior to the other two 1-Linear, 2-Fisheye, 3-Overview+Detail

11. Thank you