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

Motivation-why analyzes reading of electronic documents

• Electronic documents are increasingly being used

• Reading plays a central role in information access and use

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

Examples-- Linear, Fisheye & Overview+Detail Interfaces

Linear Fisheye Overview+Detail

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

Usability(1)-Effectiveness

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Linear Fisheye O+D

Essay/AGEssay/SGQ-A/AGQ-A/SG

• 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

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 Fisheye0

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Linear Fisheye O+D

Overall

Usability(3)-Efficiency1-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

Efficiency (the smaller the better)

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Tim

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sage

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Essay

Q-A

Usability(4)-Reading Patterns1-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

Frequency (The smaller the better)

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times

Initial orientation

Linear readthrough

Review

Average duration time (The smaller the better)

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Tim

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in) Initial Orientation

Linear readthrough

Review

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

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Overall points (5 points)

Overall points

1-Linear, 2-Fisheye, 3-Overview+Detail

Thank you