Characterising Browsing Strategies in

the World Wide Web

Lara D. Catledge & James E. Pitkow

Presented by:

Mat Mannion, Dean Love, Nick Forrington & Andrew Ingram

Overview

• Summary of Paper

• Further research

• Relevance to today’s browsing strategies

• Conclusions

Part 1: Paper Summary

Summary of the paper

• Context of the paper

• Age

• Experimental population

Browsing Strategies

1. Search Browsing: directed search – goal is known

2. General Purpose Browsing: following links that have high likelihood of leading to interesting content.

3. Serendipitous: Completely random

MoreFocusedBrowsingIntention

Drunk

Browsing vs. Searching

There is a tension between designing for browsers and designing for searchers. A hierarchical searchable database may work well for searchers, but not as useful for those just browsing for unexpected results.

First step in solving the problem was to determine what strategies are in use.

This information was obtained experimentally

Data Collection

• Special version of XMosaic coded to log user interface events at Georgia Institute of Technology's College of Computing

• Study conducted for 3 week period in August 1994

• Final log file comprised over 43,000 events with each uniquely identifiable

Results• 80% of requests used http• Following hyperlinks accounted for 52% of all

requests• “Back” command closely followed with 41%• Most users didn’t make use of hotlist (bookmarks)

and history functions• Only 10% of events activated via keyboard• Popular sites didn’t match the sites put on the hotlist

Results Continued• Pattern Detection Module (PDM) algorithm used to

identify repeating sequences of site and document accesses– For example a user going from www.gatech.edu to

www.ici.edu to www.ncsa.uiuc.edu a total of 7 times would be identified as a path length of 3 with a frequency of 7.

• An analysis of lengths of paths within each site visited for each user was performed.

Frequency and Path Length Analysis• Previous graph gives:

Frequency = -0.24 x path length

• Using the 3 Characterisations, the following classifications can be made:– Serendipitous Browser (slope < -0.24) – avoid

repetition of long sequences– General Purpose Browser (slope = -0.24) – Users

perform as expected, 1 in 4 chance of repeating complex navigation

– Searcher (slope > -0.24) – performs long sequences often

Within-Site Navigation• Backtracking (via use of “Back” command) heavily

used, can be visualised as hub-based browsing• Typical example would be:

– http://www.cc.gatech.edu/people/– http://www.cc.gatech.edu/people/People.Faculty.html– http://www.cc.gatech.edu/gvu/people/Faculty/Neff.Walker.html– http://www.cc.gatech.edu/people/People.Faculty.html– http://www.cc.gatech.edu/gvu/people/Faculty/Piyawadee.Sukaviriya.html– http://www.cc.gatech.edu/people/People.Faculty.html– http://www.cc.gatech.edu/gvu/people/Faculty/Michael.J.Sinclair.html– http://www.cc.gatech.edu/people/People.Faculty.html– http://www.cc.gatech.edu/people/

• As example shows, users rarely reach a depth of more than a few pages before returning to entry point

• Paper suggests sites should be organised to exploit this user behaviour

Conclusions of the paper• That there are three different types of

browsing strategy• These strategies can be matched to

empirical results • That these strategies were valid for pre-

web hypertext browsing, and remain so• Website designers should design with

these user groups in mind

Part 2: Subsequent Research

Linda Tauscher and Saul Greenberg

• Two separate papers– How people revisit web pages: empirical

findings and implications for the design of history systems, 1997

• Partially based on Catledge and Pitkow’s data

– Revisitation Patterns in World Wide Web Navigation, 1997

• Made conclusions on patterns of information seeking

Web page revisits• 58% of web pages in a single session are re-

visits– Changing information on pages– Further exploration of a page– Special purpose pages

• Search engine• Home page

• Information seeking is influenced by browser ergonomics– It is very easy to go “Back” in a web browser

Seven browsing patterns• First-time visits to a cluster of pages• Revisits to pages• Page authoring (refreshing changes)• Web-based applications• Hub-and-spoke (navigating to each new page

around a central page)• Guided tour• Depth-first-search (link paths followed without

necessarily returning to the source pages)

Huberman, Pirolli, Pitkow and Lukose

• Strong Regularities in World Wide Web Surfing, 1998– Regularities of surfing patterns– Mathematical law of surfing– Massively larger sample than previously studied

• In a single day:– 23,692 AOL users– 3,247,054 pages– 1,090,168 unique pages

• Also studied statistics of Xerox external site– Can predict number of visitors to a single page from its’ link

topology– Implications in e-commerce websites

Choo, Detlor and Turnbull• Information Seeking on the Web: An

Integrated Model of Browsing and Searching, 2000– Many different strategies for information seeking– Sophisticated search techniques– Implications for brand building

• Brands are a substitute for information• Information searching strategies make information more

freely available

Episodes of information seeking on the web

Part 3: Relevance today

Are the initial results valid today?

• Mosaic provided basis for modern browsers– Missing a lot of features compared to

newer browsers– but browsing experience is similar

XMosaic

Mozilla Firefox

New Features that could affect browsing strategy• Search engines

– Not widely used at the time of study– Didn’t crawl

• Forms– Not supported by all browsers at the time of the study

• Dynamic Pages / Personalisation– Pages can be generated for a particular user

• Scripting– Webpages becoming more like applications

• Really Simple Syndication (RSS)– Used to keep track of sites with changing content (news,

blogs etc).

Evaluation of findings

• Heavy use of back button – can now use…– Mouse gestures– Additional mouse & keyboard buttons

• Paper envisioned page designers creating different “views” for different types of users (browsers & searchers)

• Instead, we have search engines for searchers• Directories for browsing

Evaluation of findings

• “alter page design on the fly based on accesses by users”– Most popular products in online stores– Also personalisation of websites (e.g.

recommendations) not predicted in paper– Although a “guided tour based on paths

most travelled” isn’t commonplace.

Evaluation of findings• Paper suggested image maps

– Not widely used• “Document designers need to be cognizant of

the classification of expected visitors”– This is generally not the case with most websites– Designers generally more aware of different

classifications in terms of browser type, screen size etc

• Problem of searching vs. browsing– With more advanced search engines, we don’t

really need to worry about this anymore

Part 4: Conclusions

Conclusions• The web has changed significantly in

ten years• The three browsing strategies still exist• An entire industry has formed to cater

for search browsing – eg. Google• Designers no longer have to cater for

this – your information can always be found

Conclusions continued

• While the three strategies exist, users will switch between them so often that offering different views for different users is not commonplace

• Though many sites offer user registration to target content more effectively

The End…

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