Introduction - Collaborative Web Search: Who, What, Where, When, and Why - page 2

1.1 COLLABORATIVE SEARCH IN CONTEXT

Collaborative search is part of the broader emerging phenomenon called social search . Social search
refers broadly to the process of finding information online with the assistance of social resources. For
example, most commercial search engines use some social resources to improve the search experience.
The results other searchers have clicked ( Joachims, T. , 2002 ) and the links other people make between
information resources ( Kleinberg, J. , 1999 ) are used in ranking Web search results, and past group
query behavior is used to suggest relevant related search keywords ( Cao et al. , 2008 ) or even replace
the user's existing query ( Jones et al. , 2006 ).
All Web content is to some degree social in nature, being primarily created and shared by people
other than the person consuming the content. Although social search is typically not used to refer to
the use of Web content in general, it can refer to searches conducted over existing databases of content
created for social purposes, such as the collection of public Twitter posts http://twitter.com/ , or
an archive of questions and answers, such as in the Answer Garden system ( Ackerman and Malone ,
1990 ). Search over databases of socially-generated content, collaborative filtering, and other similar
mechanisms represent implicitly social activities. Users of such systems are not actively attempting
to assist each other in their search efforts, and they may not even be aware that their actions have
influenced others' search outcomes.
However, other people often explicitly aid an individual's search task in many steps of the
search process. In a 2008 survey, Wells and Rainie (2008) found that people used a mixture of
internet searching and social resources (i.e., phone calls or face-to-face meetings) in order to answer
many types of questions. Some researchers have proposed formal models to describe the interplay of
online information seeking with the use of social resources. For example, Pirolli, P. ( 2009 ) developed
a model of social information foraging, and Evans and Chi ( 2008 ) described the various stages in the
search process when users engaged with other people. Some researchers have built special tools to
integrate explicit social information with search engine use, such as HeyStaks ( Smythetal. , 2009 ),
a browser plug-in that enables users to mark search results as relevant; these results are then boosted
in the rankings of socially connected users who do searches on similar topics.
In all of the above examples of social search, social information is used, either implicitly or
explicitly, to improve what is primarily an individual user's search experience. Collaborative search ,
which we focus on in this lecture, is the subset of social search where more than one user share an
information need, and they actively work together to fulfill that need. Although collaborative search
is our main focus, we occasionally refer to findings from the broader social search literature when
such findings can inform the design of more explicitly collaborative systems.

1.2 SCENARIO: COLLABORATION TODAY

To aid in our discussion of collaborative search, we consider a scenario representing collaborative
search as it occurs today. The scenario occurs shortly after Martha's breathing difficulties were
diagnosed by her doctor as asthma. Immediately after the diagnosis, Martha headed back to her