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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Visual Interfaces for Improved Mobile Search</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Karen Church</string-name>
          <email>karen@tid.es</email>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Barry Smyth</string-name>
          <email>barry.smyth@ucd.ie</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Nuria Oliver</string-name>
          <email>nuriao@tid.es</email>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Author Keywords</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>CLARITY, University College Dublin</institution>
          ,
          <addr-line>Belfield, Dublin 4</addr-line>
          ,
          <country country="IE">Ireland</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Mobile Search</institution>
          ,
          <addr-line>Search Interfaces, Social Search, Social Networking, Mobile Web, Context, Preferences, Location, Time</addr-line>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Telefonica Research</institution>
          ,
          <addr-line>Via Augusta 177, 08021, Barcelona</addr-line>
          ,
          <country country="ES">Spain</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2009</year>
      </pub-date>
      <issue>1</issue>
      <abstract>
        <p>The Mobile Web promises a new age of anytime, anywhere information access to billions of users across the globe. However, the Mobile Internet represents a challenging information access environment, particularly from a search standpoint. In this paper we present two visual interfaces for improved mobile search. First, we present SearchBrowser, a map-based interface that offers richer end-user interactions by taking into account important mobile contexts including location and time. Second, we consider the social context of mobile search and present SocialSearchBrowser; a proofof-concept interface that incorporates social networking capabilities to improve the search and information discovery experience of mobile subscribers.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>The early work presented in this paper was carried out while
Karen Church was a PhD student in University College Dublin.
This material is based on works supported by the Science
Foundation Ireland under Grant No. 03/IN.3/I361 and Grant No.
07/CE/I1147. The later work, i.e. the SocialSearchBrowser
prototype is being carried out at present in Telefonica Research.
yCLARITY: Centre for Sensor Web Technologies.
1http://www.un.org/apps/news/story.asp?NewsID=28251
&amp;Cr=Telecommunication&amp;Cr1</p>
      <p>However, the Mobile Internet represents a challenging
information access environment, particularly from a search
standpoint. Limited screen-space and restricted text-input and
interaction capabilities exacerbate the shortcomings of modern
Web search. To date most mobile search interfaces are
simple adaptations of standard Web interfaces, where users are
presented with a ranked list of results. For mobile search to
succeed we need to think beyond simply query-based
interfaces and towards interfaces that can offer richer interactions
by taking into account important mobile contexts that have
an impact on mobile users needs.</p>
      <p>
        In this paper we focus on the mobile search interface and
we offer on a more radical rethink of mobile search. It has
always been our contention that mobile search differs
significantly from Web search, not just because of the devices but
also because people’s information needs differ when mobile.
Previously we examined the information access patterns of
real mobile subscribers using log analysis techniques [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ].
More recently, we investigated mobile information needs
insitu, examining the unique contextual factors that impact on
user needs [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. Our findings indicate that when users are
mobile there is a clear location and temporal dependency
in their information needs. Furthermore, we found that the
needs that arise when mobile cannot always be answered by
existing search engines, because existing search engines do
not take key mobile contexts into account.
      </p>
      <p>Based on the findings of these previous studies, we devised
two new visual interfaces for mobile search, both designed to
emphasise the importance of location, time and preferences
as key elements of search context. Unlike traditional search
interfaces, which require user input before providing
information to end-users, our interfaces give mobile users
interesting information from the beginning. Our approach is
designed to change the mobile search paradigm. The interfaces
present historical query, comment and result-selection data
for users to navigate through on an interactive map-based
interface. The rich user interface enables users to interact with
the past activities of other users, execute searches, view past
result-selections and filter queries based on context
information. In short by presenting users with information about
what others are searching for we believe we can offer an
improved search experience.</p>
      <p>
        This paper is organized as follows. In the following section
we present some related work. Next, we describe
SearchBrowser, a map-based interface that offers richer end-user
interactions by taking into account important mobile
contexts including location and time and we describe the results
from a recent user study. Based on the outcomes of this
evaluation and the findings from our diary study [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ], we turn to
the Social Web and explore the social context of search. In
the final section of this paper we propose a proof-of-concept
interface called SocialSearchBrowser that incorporates
social networking capabilities to improve the search and
information discovery experience of mobile subscribers.
RELATED WORK
The focus of this paper is on novel mobile search interfaces
that utilize key mobile contexts. There has been a range
of previous research that investigates improved search
interfaces in the general Web space. Our current work combines
work on exploratory search, mobile search and social search.
As such we have identified three areas of related research:
Exploratory Search
Traditional approaches to Web search typically involve a user
submitting a query via a search box and viewing a list of
results. More recently, a new class of search has emerged,
called exploratory search [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ], which supports the
exploration and discovery of information through both querying
and browsing strategies. There have been a number of
exploratory search systems developed to date. For example,
Hearst presents Tile-Bars [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ], a technique which uses the
structure of text to provide a visualization aid to end-users.
TileBars help users to visualize the document length, query
term frequency and query term distribution, thus assisting in
relevance assessments of documents. Yee et al. [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ] presents
an alternative interface for exploring large collections of
images using hierarchical faceted metadata and dynamically
generated query previews. While recent work by Alonso et
al. [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] describes an interface that utilises timeline data to
enable effective presentation and navigation of search results.
Mobile Search
Another area of research related to this paper concerns
innovative approaches to mobile search interfaces. FaThumb
[
        <xref ref-type="bibr" rid="ref11">11</xref>
        ] is a user interface designed for navigating through large
data sets on mobile devices providing a more efficient means
of mobile search. FaThumb uses faceted metadata
navigation and selection as well as incremental text entry to narrow
the results. A user evaluation demonstrated how the facet
based navigation is faster for less specific queries.
Questions not Answers (QnA) [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ] also provides an
interesting alternative to the traditional search interface. Rather
than examining how to provide high-quality search results,
the QnA approach is to provide access to previous queries
posted from the user’s current location. This novel user
interface displays queries made by other people in a given
location using a map-based interface, providing users with an
enriched sense of place. By clicking on the queries users
can execute the displayed search. In a live user evaluation
[
        <xref ref-type="bibr" rid="ref2">2</xref>
        ], users found the interface to be useful and they enjoyed
the increased level of interaction the interface enabled.
Social Search
      </p>
      <p>
        More recently researchers are investigating the social side to
Web search. For example, Collaborative Web Search (CWS)
involves utilising the search histories (i.e. queries and
resultselections) of communities of like-minded individuals. In
[
        <xref ref-type="bibr" rid="ref7">7</xref>
        ], Freyne et al. looks at integrating CWS with social
browsing, i.e. leveraging past browsing behaviour of users to guide
others to relevant web content, to produce an integrated
social information access service. Preliminary results from a
live user trial indicated that the use of social cues helps users
to access relevant information in an easy and efficient
manner.
      </p>
      <p>
        Another approach is to exploit Web 2.0 technologies,
specifically Web annotations, to improve Web search. The basic
premise is that by allowing users to annotate search results
and to share these annotations with others, the search
experience can be improved. In [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ], Boa et al. propose two
novel algorithms, SocialSimRank (SSR) and SocialPageRank
(SPR) to explore the role of social annotations on
similarity ranking and static ranking respectively. Results from an
evaluation using a del.icio.us dataset shows that both SSR
and SPR could benefit Web search significantly.
      </p>
      <p>Another related area of interest is social search. Social search
in this context involves exploiting different forms of human
judgements, ratings and interactions to improve the overall
search experience. For example, Microsoft’s U Rank2, is a
prototype search engine that allows people to edit, annotate
and organise search results. U Rank enables users to
collaborate with one another through sharing and recommendation
of search results in easily accessible lists.</p>
      <p>
        Most relevant to our current work is utilizing social
networks to enhance search results and online interactions. In
[
        <xref ref-type="bibr" rid="ref8">8</xref>
        ] Golbeck and Wasser introduce an application called
SocialBrowsing which works by analyzing web page content
and highlighting words or phrases which have some
contextual social information. In [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ], Mislove et al. present
PeerSpective, an experimental prototype which exploits both
the hyperlinks of the Web as well as the social links within
communities of users to inform a new search result
ranking approach. An evaluation of the PeerSpective search
engine showed that it performs well in terms of
disambiguation, ranking and serendipity of search results.
      </p>
      <p>Our Proposal &amp; Contributions
Our current work is similar in nature to the QnA approach.
The QnA system essentially tags queries with a location.
These queries are displayed on a map-based interface
enabling users to visualise the search space. The QnA
prototype does not, however, provide any means for a user to
filter queries, other than by location. Given that the
volume of queries at specific locations is likely to be quite high
and there is no means to filter queries, the QnA prototype
raises a new interface/presentation challenge. Furthermore,
our prototypes focus on the social side to mobile search
allowing users to interact with the result-selections and
comments of other users. In the SocialSearchBrowsr application,
we investigate this social context further by utilizing social
2http://research.microsoft.com/projects/urank/
networks for improved information access. We think this
is a core area to address given the unique characteristics of
the mobile space. Thus the core contributions of this
paper are as follows: (1) we present SearchBrowser, a
contextaware mobile search interface that enables situated discovery
of information, (2) we describe a recent user evaluation of
SearchBrowser and demonstrate some initial positive results
and (3) we propose SocialSearchBrowser, an extension of
SearchBrowser, which explores the social context of search
by incorporating social networking to improve the
information access experience of the end-user.</p>
      <p>THE SEARCHBROWSER INTERFACE
The basic premise behind the SearchBrowser interface is that
by allowing users to see what other users have been
searching for and interacting with, we can improve the search
experience. The interface utilises contextual information such
as location and time to provide a unique experience. The
interface provides mobile users with information more
proactively, thus encouraging discovery of content. The
prototype3 consists of a text box that allows users to issue new
queries and a small map centered at the user’s current
physical location. The map shows queries submitted by other
users in that location and two sliders at the bottom of
interface are used to filter the queries displayed on the map.
The Map Interface
When the user first initialises the application, he/she is shown
a map centered at their current location (Figure 1). The map
shows all recent queries entered by other users in that
location. We refer to these queries as the prime set. The
map is updated periodically so that newly entered queries
are displayed. Queries submitted by other users, but without
any result selections, are identified by a small magnifying
glass with an associated label (See Figure 1 icon (1)), while
queries that have resulted in the selection of at least one Web
search result are identified by the small globe/Web icon with
an associated label (See Figure 1 icon (2)). The label
displays the actual query text. If a query or result-selection
has a comment associated with it, the associated icon is
augmented with a small user image. Comments can come in
the form of answers, suggestions, tags, descriptions, general
comments/remarks, etc. Queries with comments are shown
in Figure 1 icons (3) and (4).</p>
      <p>
        Search Histories
Clicking on the query icons/labels opens an information
window/bubble (Figure 2), showing the query, the time the query
was last executed and a link to execute the query in
question. If the query lead to a result-selection the information
window also displays the most recent result-selections.
Furthermore, if the query has any comments associated with it,
a link to view these comments is also shown (Figure 3
illustrates the comments facility). Users can choose to go directly
3The work presented in this paper builds upon earlier work
presented in [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. We have extended our previous work by: (1)
enhancing the interface component of the SearchBrowser application, (2)
by adding a comments feature in which users can add comments to
queries and (3) by carrying out an initial user evaluation designed
to test the basic utility of the interface.
      </p>
      <p>1. Query
3. Query with comments</p>
      <p>SearchBrowser interface on startup
to one of the listed URLs or to re-execute the query4.
To help users distinguish between popular queries, the icon
sizes of the queries change based on their popularity. We
use a simple measure of popularity based on the number of
times the query has been submitted and the amount of
resultselections and comments associated with the query. Smaller
icons indicate a low level of interactivity, while larger icons
indicate a high level of interactivity.</p>
      <p>Context Sliders
At the bottom of the interface there are two sliders. One
slider represents time while the other slider represents query
similarity. Users can manipulate the sliders to adjust the
set of prime queries and to filter these queries. For example,
users can adjust the time slider to go back in time and display
queries submitted during different time periods. Thus rather
than simply displaying queries submitted now (i.e. in the last
couple of hours), users can view queries submitted over the
entire day, yesterday, the last few days, last week, etc.
The same principle applies to the query similarity slider.
However, instead of time, the query similarity slider filters
by query term overlap. When a user accesses the application,
the system automatically calculates the similarity between
the user’s queries and all other queries in the dataset.
Moving the query similar slider, changes the similarity threshold
and thus filters queries from the prime set. In the following
section we describe our evaluation of SearchBrowser.
4Note that if a user chooses to re-execute a query they will receive
a set of results from the standard Google search engine.</p>
      <p>EVALUATING SEARCHBROWSER
We had two main aims in carrying out an evaluation of the
SearchBrowser interface. First, we wanted to assess the
effectiveness of the interface, focusing on key features of the
interface and their usefulness. Second, we wanted take the
first steps to investigate the potential of the new interface to
encourage discovery of new interesting content.</p>
      <p>Dataset
To demonstrate the range of functionalities supported in the
SearchBrowser application, we needed a source of queries,
comments and result-selections as the basis of our dataset.
To generate the seed queries, we manually extracted &gt; 200
entries from the online WikiMapia service, focusing on
entries with a latitude/longitude in the central Dublin, Ireland.
WikiMapia5 is a Web 2.0 application designed to encourage
users to describe the world. WikiMapia allows users to mark
areas on a Google map and describe those areas using titles,
descriptions, tags, categories, images and links to external
URLs. Given that each entry in WikiMapia includes rich
descriptive information, along with an original creation date
and a physical latitude/longitude value, it provided a good
basis to generate seed user queries for our evaluation.
To generate realistic queries we then asked 3 different users
to view the list of WikiMapia entries and to formulate a
query for each6. This resulted in 444 generated queries which
were then used as a basis for the prime dataset7. For each
query, we extracted the associated WikiMapia entry,
generated a random date and latitude/longitude within the
chosen time period and given location boundary, i.e. central
Dublin)8. Any URLs associated with the WikiMapia entry
were used as the result-selection(s) and if the entry had tags
associated with it, we used the corresponding title/name as
the comment. The outcome was a set of time-stamped,
geocoded, query, comment and result-selection data.</p>
      <p>Participants &amp; Methodology
20 participants took part in the study, 18 male and 2 female.
The participants comprised a mix of computer science staff
and post-graduate students from UCD, ranging in age
between 25 and 40 (average: 30, standard deviation: 4.23).
85% of users had some previous Mobile Internet experience,
but most of these users (approximately 60%) accessed the
Mobile Internet on an infrequent basis.</p>
      <p>The participants carried out the experiment online using a
standard Web browser. The Web browser emulated the
SearchBrowser interface by using similar screen real-estate to an
iPhone (320 x 480 pixels). Participants were asked to (1)
to familiarise themselves with the interface for the first few
minutes of the experiment and (2) to formulate and submit
five queries of their own using the interface. We informed
participants that the queries were open-ended, however, we
did ask participants to bear in mind that the interface is
designed for mobile devices and as such would be used while
on-the-go. When generating their queries, we asked
participants to try to think of things they might need/like to find
out if mobile and in the location presented on the map.
Before they were exposed to the interface the participants were
presented with a description of the various features of the
interface. At the end of the evaluation, users were presented
with a post-task questionnaire designed to measure their
subjective reactions to the interface9.</p>
      <p>Usage Results
6Each participant was presented with the same list of WikiMapia
entries and participants were instructed to generate queries for as
many entries as possible out of the list of &gt; 200 entries.
7We are aware that artificially generating queries in this manner
is a limitation of this study. However, without deploying
SearchBrowser, it is impossible to obtain a realistic source of queries. For
users to evaluate the application we needed to be able to show
them a sample of queries, comments and result-selections and
WikiMapia offers a rich set of geo-coded data as the basis.
8A note on random location values: in a realistic setting it is
unlikely that a user will always submit a query related to an exact
physical location. For example, if the user wants to know where
they can find a coffee shop on a particular street, the query could be
generated anywhere along that street or within close vicinity to that
street. Therefore, we opted to generate a random latitude/longitude
within close vicinity to the actual latitude/longitude value.
9This study allowed us to gather interesting feedback about the
interface and it’s overall usability. We are aware that the evaluation is
limited in that is does not take place in a mobile setting, however,
we feel that the evaluation in it’s current form still yields some
interesting results and represents an important first step in our
ongoing work in the mobile search space.</p>
      <p>In this section we focus on the quantitative results by
exploring the user interactions with the map-based interface as
well as general usage statistics.</p>
      <p>Interactions with the Map Interface
Using click-thru and mouse-over data we were able to
analyse what features of the map and user interface the
participants interacted with. Although the level and type of
interaction with the SearchBrowser interface is likely to be different
in a real mobile setting, we were still interested in
examining interactions with the map so that we could gather some
insights into which features of the current user interface
participants were drawn too. Overall we found a high degree
of interactivity from end users. All users interacted with the
map based interface using both zoom and drag functions to
navigate. All users clicked on either a query or result
selection marker and opened an information window bubble.
We found that 95% of users clicked on the query markers
while 75% of users clicked on the result-selection markers.
We also found a high degree of interactivity with the
various markers/query icons, with mouseover events tracked for
the vast majority of users. Thus, users did interact with the
queries and past result-selections of other users.</p>
      <p>We found that most users selected search results within the
SearchBrowser application. However, only 10% of users
chose to click on a URL in the result-selection bubbles, thus
indicating a low level of interactivity with the past
resultselections of other users. Our later analyses indicate that
poor search results may have been the main cause for such
a low level of interaction. We also found that 70% of users
chose to view the comments of other users, but less than 50%
chose to generate comments of their own10.</p>
      <p>
        Search Usage
The results so far demonstrate that from an interactivity
standpoint, all users engaged with the SearchBrowser interface.
Table 1 presents some basic usage statistics. The participants
generated almost 300 queries, 126 of which were newly
generated queries (i.e. submitted via the search box and not
through interactions with queries presented on the map
interface). Interestingly we find that 45% of all newly submitted
queries by participants lead to at least one result-selection.
This represents a significant increase on the success rates
found in [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ] in which only 11% of mobile queries lead to the
selection of at least one search result.
      </p>
      <p>Questionnaire Results
In this section we examine the participants’ subjective
reactions to SearchBrowser. At the end of the evaluation, users
were presented with a post-evaluation survey. The survey
was designed using a combination of questions from
wellestablished usability questionnaires such as QUIS11 and the
10In most social websites, the majority of users don’t actively
participate in the generation of new content. In an analysis from Yahoo!
Groups, 1% of users actively create new content, 10% of users
actively contribute to such content (e.g. replying to a blog post) while
100% of users benefit by reading/viewing the content generated by
the others. See http://www.elatable.com/blog/?p=5.
11Questionnaire for User Interface Satisfaction:
http://hcibib.org/perlman/question.cgi?form=QUIS</p>
    </sec>
    <sec id="sec-2">
      <title>Measure</title>
      <p>Total
Mean (per-user)
Min
Max
SD
# Users
% Users</p>
      <p>IBM Computer Usability Satisfaction Questionnaires12. We
also included some more detailed usability and user-acceptance
questions focusing on key aspects of the SearchBrowser
interface. Participants rated their agreement with various
statements on a 7-point anchored likert scale13, with a rating
of 1 indicating “strongly disagree”, a rating of 7 indicating
“strongly agree”, while a rating of 4 indicates “neutral”. The
survey questions fell into three categories: (1) overall
satisfaction, (2) application features and (3) user interface (UI).
A full list of questions can be found in the appendix.
Overall Satisfaction</p>
      <p>Q M1 SD</p>
      <p>M2</p>
      <p>M3
1
2
3
4
5
6
7
8
4.50
5.85
5.55
5.85
3.70
4.00
5.65
5.30
1.47
1.35
1.28
1.14
1.66
2.00
1.27
1.42
5
6
6
6
4
4
6
5
5
7
5
7
4
4
6
5
1
1
0
0
0
1
2
0
0</p>
      <p>Frequency Count
2 3 4 5 6
0 5 2 7 4
1 0 2 3 6
1 0 2 6 6
0 0 3 5 4
5 3 6 1 3
3 4 4 2 1
1 0 2 4 8
1 0 5 6 2
7
1
8
5
8
1
4
5
6</p>
      <p>The list of satisfaction questions can be found in Table 7 in
the Appendix. Overall, the participants’ subjective
assessment of satisfaction with the application was positive, with
an average response of 5.05. Participants found the
application easy to use (q2=5.85) and easy to learn (q4=5.85). They
found performing tasks to be straightforward (q7=5.65) and
in general felt that they could imagine using the application
while mobile (q8=5.3). However, users were unbiased in
their rating of statement 6 regarding expected functions and
capabilities, and we found the general satisfaction rating
assigned by users was more neutral (q1=4.5). We attribute this
to one key issue: users found it somewhat difficult to find
the information they needed/wanted (q5=3.7). The goal of
this evaluation was not to assess the search result quality, but
rather the interfaces effectiveness and in this evaluation we
were limited by the underlying search engine. We used the
Google search API for the search component of the
application. We attempted to localise the queries by appending the
12http://drjim.0catch.com/usabqtr.pdf
13http://en.wikipedia.org/wiki/Likert scale
Q</p>
      <p>SD
terms Dublin and Ireland to participant queries before
issuing them to Google. However, one of the main comments by
participants was that the search results were not as localised
as they expected/wanted.</p>
      <p>Application Features</p>
      <p>M2</p>
      <p>M3</p>
      <p>The list of feature questions can be found in Table 5 in the
Appendix. We found the majority of users were almost
unbiased in their responses to the first set of questions
regarding the query feature. For example, we found that in
general participants didn’t find that they interacted with queries
frequently (q5=3.55) and they were unsure as to whether
other people’s queries helped them form their own queries
(q6=4.2). However, users did rate statements 7, 8 and 9
positively, indicating that the queries provided an
understanding of the type of information that is relevant to the location.
Users liked the ability to browse other user queries.
Furthermore, they thought it was an interesting way to discover new
information (q8=5.85) and it helped them learn about other
people in the area (q9=5.4). One of the main aims of the
evaluation was to assess whether users liked the exploratory
interface provided by SearchBrowser and these initial results
indicate that this may be the case.</p>
      <p>Although participants found the ability to view result-selections
useful (q11=5.60), they found they did not interact frequently
with the result-selections of others (q11=3.8) and were
neutral in their opinion as to whether the result-selections of
other users provided them with additional information about
the query (q12=4.45). We attribute this finding to the poor
quality of the search results presented to users. It is likely
that the ratings for such features would increase if the search
results returned improved.</p>
      <p>The comments feature resulted in a relatively neutral rating
on average (q14=3.95, q15=4.10). In fact we find that
participants were quite divided in their opinion on the
usefulness of the comments feature. For example, when asked if
the comments feature helped them to learn more about the
query, we find that 10 users agreed, 3 users were unbiased
and a further 7 users disagreed (q15). Interestingly we found
that users were more in agreement that they added comments
to their own queries (q19=3.45), rather than adding
comments to other people’s queries (q18=1.55). After examining
the remarks of participants about the comments feature, we
found that some users were not clear on what constitutes a
comment. This is something we look at improving in the
SocialSearchBrowser application.</p>
      <p>User ratings for the two slider features were generally
positive. We found that 12 users (60%) assigned a positive
rating when asked if the time slider is useful, while 13 of the
users (65%) liked being able to filter queries based on time.
Users found the time slider more intuitive and as such
interacted with the time slider more frequently. Reaction to the
query similarity slider was less positive overall. For
example, users were quite neutral when asked if the query
similarity slider was useful (q23=4.15), however they were quite
positive when asked if they liked being able to filter queries
based on query similarity (q25=5.05). Interestingly, we find
that when we examine the frequency count for each of the
7 ratings assigned to the slider questions, the most popular
rating is strongly agree (score of 7), indicating that the users
who did like the slider features found them very useful.
Overall the SearchBrowser features were well-received by
participants, with the queries and time slider features rated
most positively out of the five feature sets. The results
indicate that with some straightforward improvements, the
remaining features (result-selections, comments and query
similarity slider) could become more effective.</p>
      <p>User Interface
The list of user interface questions can be found in Table
6 in the Appendix. Most of the participants were satisfied
with the interface (q1=5.05), found the interface pleasant
(q2=5.9), intuitive (q17=5.9) and liked interacting with the
interface (q3=5.75). Users also found the interface easy to
interact with (q14=6.2). Furthermore, users were able to
easily explore the various features of the map (q16=5.9)
indicating that perhaps such an interface would work well as a
information discovery tool in the mobile space. Users noticed
the queries on the map (q4=6.45), enjoyed the icons used to
represent queries (q5=5.45) and were somewhat positive as
to the intuitiveness of the query icons (q6=4.85).</p>
      <p>When examining the two sliders, we find that users rated
the time slider more highly, indicating that they noticed the
time slider (q7=6.45), they found it intuitive (q8=6.3) and
they liked the time slider (q9=6.3). The ratings assigned to
similar statements for the query similarity slider, although
positive, leaned more towards an unbiased rating. As
mentioned in previous sections, we included the time and query
similarity sliders in the SearchBrowser application so that
users could quickly and easily filter the set of queries
displayed on the map. However, even with such features, we
find at times that the interface became cluttered with
information (q15=4.4) thus making it more difficult to read the
information presented (q13=4.95).</p>
      <p>Overall we found the response to the user interface by
participants was very positive, with the majority of users assigning
top marks to the vast majority of statements, thus indicating
that the current SearchBrowser interface design is both
usable and aesthetically pleasing.</p>
      <p>Q</p>
      <p>SD</p>
      <p>As well as asking users to rate their perceptions of the
SearchBrowser application on the 7-point likert scale, we also asked
users some more general freeform questions. 90% of users
said they would use the SearchBrowser application if the
service was easily/readily available. When asked under what
circumstances would they use such an application,
participants submitted a range of responses including, if there were
in an unknown physical place (e.g. a new city), to find
information about local services/products, to keep up-to-date
with current events and finally to find directional/travel-related
information. Interestingly, users also commented on the
social aspect of the application, indicating that the social side
to the SearchBrowser application could be very useful for
query recommendations.</p>
      <p>
        Overall the results of the evaluation were positive. The
SearchBrowser study represented an important first step in
evaluating this type of interface and it provided us with some
valuable feedback regarding the interface components and the
supported interactions. However, the evaluation results also
encouraged us to re-think some elements of the prototype.
Furthermore, results from a recent diary study of mobile
information needs indicate that mobile users seek fresh content
that is location and time specific and is influenced by social
context [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. Although existing search giants attempt to
provide some solutions — for example, Google’s mobile search
facility utilizes a users default location in order to contextual
search results14 — these solutions don’t go far enough.
One of the unique features of the SearchBrowser interface
is that it provides a comments facility which allows users to
add comments, tags, answers and suggestions to the queries
submitted by other users. The key idea behind this facility
is that it allows users to provide helpful information to assist
other users with their information needs, thus embracing the
social side to mobile search. Although the comments
feature represented a simply first step at utilizing people-power
to enhance the search experience of mobile users, we
believe that there are a number of opportunities in this research
space. In particular, we think that there is great potential
in utilising a users social network as a source of valuable
query answers, comments, etc. Furthermore, incorporating
a users social network into the mobile interface would
allow some novel and interesting filtering methods based on
‘friend’ queries. Thus we have developed a prototype called
SocialSearchBrowser which allows users to execute queries
in various physical locations but also enables friends of the
current user to answer these queries in real-time. In the
following section we describe SocialSearchBrowser in more
detail.
      </p>
      <p>
        SOCIALSEARCHBROWSER
Human beings, by their nature are social creatures. We live
by communicating with others, building relationships and
forming friendships. In fact, many people view the mobile
phone as a social communications device, that is, a device
which can be used to stay in contact with friends and family
[
        <xref ref-type="bibr" rid="ref13">13</xref>
        ]. Online social networking sites such as Facebook and
MySpace have experienced a huge increase in usage in
recent times, with more and more users seeking novel ways of
interacting with their friends and family15. And in the near
future it is likely that mobile phones will be used as the first
port of call in accessing these online social networks.
The SocialSearchBrowser is made up of two components.
The first component is a map-based interface that works in a
similar way to the previously discussed SearchBrowser
application. The second component is a Facebook application.
The interface consists of a text box that allows users to issue
queries, a small map centered at the user’s current physical
location which displays all queries executed in that location
and three sliders at the bottom of the interface for filtering
the set of queries displayed (See Figure 4). We have
introduced a new social slider which allows users to show queries
submitted by everyone or to display only queries submitted
by friends. Manipulating the social slider changes the level
of friendship threshold and as such updates the queries
displayed on the map. The premise behind this slider is that
users are likely to be interested in the queries and
interac14http://www.google.com/m
15The latest statistics from Facebook highlight that there is
currently 150 million active users worldwide (Jan 2009). See:
http://www.facebook.com/press/info.php?statistics
tions their friends have participated in.
      </p>
      <p>The Facebook application comprises of an information page
showing all queries submitted through the SocialSearchBrowser
interface. The information page lists the query submitted,
the name of the user who submitted the query, the location
of the user and a timestamp indicating when the query was
submitted (See Figure 5). Clicking on the query opens a
more detailed information page (See Figure 6). The
detailed page shows relevant query details but also displays
a Google map of where the user was at the time the query
was executed. It also shows a list of any answers/comments
submitted for the query and a form for entering new
answers/comments. In this way Facebook users can see what
queries their friends have executed on the go, where and
when their friends executed these queries and any answers
provided to these queries. To envisage how the
SocialSearchBrowser would work, imagine the following scenarios:
Amy is wandering around Plaza de Catalunya in Barcelona
as part of her weekend away in Spain. She wants to know
where she can find a nice restaurant that serves tapas but she
wants to avoid touristy places. Amy takes out her iPhone,
opens the browser and connects to SocialSearchBrowser. Amy
is presented with a map centered at her current location. The
map displays other queries and user interactions that have
taken place in her current location. Amy is able to get an
idea of the types of needs that arose from other mobile users
in this location. Amy doesn’t see any queries on the map
related to tapas so she decides to submit her own query. Thus,
Amy enters the query “good tapas” via the
SocialSearchBrowser interface. Amy is presented with a localized list of
Web search results for her query. At the same time a
notification is sent to Amy’s facebook friends indicating that Amy
is in Barcelona and that she’d like some help with a query. A
few minutes later Amy is alerted that one of her friends has
submitted an answer to her query. Amy returns to the map,
clicks on her query and is shown the answer(s) submitted by
her friend(s). Perfect, now Amy knows exactly where to go
for great tapas!
David is in the middle of Dublin city center, sipping on a
coffee and is thinking about what to do this weekend with
friends. He takes out his iPhone, opens the browser and
connects to SocialSearchBrowser. David is presented with a
map centered at his current physical location. David is able
to see straight away that other users have entered queries
like “coffee to go” and “salsa classes” in this location. David
decides he wants to explore what else other people in this
location have been interested in. He moves the temporal slider
towards the earlier marker and the map is updated with lots
of different queries entered in this location. David see’s lots
of queries related to comedy events. David then uses the
social filter to show only queries submitted by his friends and
he notices that his friend Tony was looking for tickets to see
a comedy show last week. David decides to call Tony to see
if he’d like to go to a comedy show this weekend.</p>
      <p>Ideally, when queries are submitted via SocialSearchBrowser,
a user’s friends will be online and will be able to offer help
immediately. This scenario could also be extended to allow
anyone to answer queries, but in this case, answers generated
by close friends of the user would be rated higher. Other
social factors could also be explored. For example, in the
current prototype we include a social slider for filtering queries
so that only queries generated by friends are displayed. We
could also investigate filtering friend locations, i.e the set of
locations where your friends executed queries, etc.
Thus, SocialSearchBrowser provides an alternative means
of mobile search and information discovery, taking into
account key mobile contexts such as location and time, while
exploiting the social context of search. Users are
encouraged to discover new, interesting content and perhaps new,
interesting places. The new prototype utilizes a users
social network to improve the information access experience,
allowing friends to provide helpful information through
realtime query answering. Furthermore the application enables
a new form of social discovery by allowing friends to share
queries and online interactions while mobile.</p>
      <p>CONCLUSIONS
Mobile information access is challenging, particularly from
a search perspective. In this paper we described two new
interfaces for improving mobile search and discovery. The
first interface, SearchBrowser, presents users with
historical query, comment and result-selection data on a rich
mapbased. The application takes important mobile contexts into
account such as location and time. Results of an initial user
trial were positive and demonstrated that the current
interface design is easy to use, easy to learn and aesthetically
pleasing to end-users. Based on user feedback from this
evaluation and results of a recent diary study of mobile
information needs, we developed an extended proof-of-concept
prototype, that explores the social context of mobile search.
SocialSearchBrowser is an innovative interface that
incorporates mobile contexts with social networking capabilities to
improve the search and information discovery experience of
mobile subscribers. SocialSearchBrowser allows friends to
provide help to mobile users in the form of answers,
comments, suggestions, links and tags, through a Facebook
application. Furthermore, the interface incorporates a social
filter which enables mobile users to filter the set of queries
displayed to show only friend queries, helping to visualise
friend queries and interactions.</p>
      <p>We are currently investigating a number of different areas
relating to the prototype. Firstly, we are in the process of
implementing a fully functional working prototype which
we plan to test and evaluate with real users in a live mobile
field study. We have also identified a number of
interesting future directions that explore the social context of search
in more detail. We’d like to consider other social filtering
approaches. For example, we could show popular friend
queries and allow users to visualize the most common
locations in which friends have had previous mobile
information needs. We could also exploit social networks to provide
personalized query and location recommendations. For
example, a mobile user might be interested to learn about a
new street in their city where a number of their friends have
submitted previous mobile queries. We’re also interested
in the automatic identification of ‘close friends’ vs ‘not so
close friends’, based on facebook activity, presence in
mobile phone contacts and other informative resources.
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
16</p>
    </sec>
    <sec id="sec-3">
      <title>Question</title>
      <p>I found other people’s queries useful
I found other people’s queries informative
I found other people’s queries intriguing
I found other people’s queries distracting
I interacted with other people’s queries
I found that other people’s queries helped
me form my own queries
Many of the queries displayed helped me to
understand the sort of information that was
relevant to the location being browsed
The ability to browse other people’s queries
is an interesting way to discover new
information.</p>
      <p>The queries helped me to learn about other
people in the area, their needs and
preferences
The ability to view other people’s past
result-selections is useful
I interacted with other people’s past
resultselections
The result-selection feature provided me
with additional information about the query
The result-selection feature helped me find
answers to the queries
I found the comments feature useful
The comments associated with a query
helped me learn more about the query
The comments associated with a query
helped me find answers to the query
I viewed other people’s comments
I added comments to other people’s queries
I added comments to my own queries
I found the time slider useful
I interacted with the time slider
I liked being able to filter the queries
displayed on the map based on time
I found the preference slider useful
I interacted with the preference slider
I liked being able to filter the queries
displayed on the map based on query
similarity
2
3</p>
    </sec>
    <sec id="sec-4">
      <title>Question</title>
      <p>Overall, I am satisfied with the search
browser interface
The interface of the search browser
application was pleasant
I liked using the interface of the search
browser application
I noticed the queries on the map
I liked the query icons
I found the query icons intuitive
I noticed the time slider
I found the time slider intuitive
I liked the time slider
I noticed the query similarity slider
I found the query similarity slider
intuitive
I liked the query similarity slider
I was able to easily read information on
the interface
It was easy to interact with the interface
The organization of information on the
map was clear
I was able to easily explore the various
map features
The interface was intuitive</p>
    </sec>
    <sec id="sec-5">
      <title>Question</title>
      <p>Overall, I am satisfied with the search
browser application
It was simple to use the application
I felt comfortable using the application
It was easy to learn to use the application
It was easy to find the information I
needed
The application had all the functions and
capabilities I expect it to have
Performing tasks is straightforward
I could imagine using this type of
application when out and about.</p>
      <p>Leaving cost aside, would you use the
search browser application if the service
was easily/readily available?
What circumstances do you think you
might find the search browser application
useful?
What did you like about the search
browser application?
What if anything did you find frustrating
or unappealing about the search browser
application?
How could we make the search browser
application more useful for you?</p>
    </sec>
  </body>
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