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The implications of Information Foraging Theory
on designing user-centered websites have not gone unnoticed. Jakob Nielsen
and Jared Spool
,
among others, have put forth considered recommendations on how to
enhance information scent on the web. Most of their guidelines, however,
tend to assume that the designer has direct control over the explicit
words used in the interface. While this is certainly the case for
browse-based websites dependent on site-wide navigation and hyperlinks,
it breaks down for search interfaces where both content and
navigation are completely dynamic.

While the principles for amplifying information scent in search-based
interfaces are complimentary to those of browse-based models, they are
yet distinct from them. Understanding how information scent applies to
search first requires an understanding of human search behavior
and the factors that affect it.

People are just like bears (only less fur)

Marcia Bates' berrypicking model

In her landmark 1989 paper, Marcia Bates
outlined search as an evolutionary
process. Users often begin with a general query, glean a few nuggets
from the initial results, reformulate their query based on that new
knowledge, and then repeat this process. Like a bear foraging for food
in the forest, knowledge seekers tend to rapidly migrate from one patch
of information to the next.




A Bloomberg terminal concept by IDEO

While this iterative behavior is true of virtually everyone using
search, there are two key factors that distinguish some users from
others: domain expertise
and search expertise
(though John Ferrara
has identified several additional factors). Some websites, for example,
may be able to assume that users are highly literate in a specific
topic, while other websites may need to design for a range of expertise
in a variety of subjects (the case for web search engines). In addition,
users experienced at using search interfaces will be more capable of
utilizing sophisticated search tools, but less experienced users will
demand less complexity.

Though domain and search expertise separate some users from others, a given user may have different goals
at different times. The two primary types of goals are recall
and exploration
.
Recall involves a straightforward retrieval of a specific fact or
document (for instance, “what it the population of Brazil?”), and can
generally be accomplished in a short amount of time. Exploration, on the
other hand, is a more subjective process. Choosing where to go on
holiday, for example, is a complex question that may take hours or even
days to decide.

Carrots and sticks: designing for information scent

Understanding the iterative nature of search and the contexts from
which users operate is the foundation for knowing how to effectively
harness information scent to improve the usability of search. Above all
else, Information Foraging Theory has taught us that users need to feel
as if they are always “getting warmer.”
As a user searches,
information scent must grow increasingly poignant, emanating a feeling
of progress to the user. When information scent is strong, users are
confident that they’re headed in the right direction. When it’s weak,
users may be uncertain of what to next, or they may abandon their search
altogether.

When information scent is strong, users are confident
that they’re headed in the right direction. When it’s weak, users may be
uncertain of what to next, or they may abandon their search altogether.

There are many practical methods for increasing information scent in
search. Some of them bear resemblance to Nielsen and Spool’s original
recommendations, but are deserving of further elaboration in the context
of search interfaces. We will trace the user’s journey from the
searchbox, to the list of search results, and end with query refinement
using faceted navigation.

The searchbox

In order for a user to have a successful search experience, he must
first locate the searchbox and successfully enter a query. These two
obvious requirements lead us to our first two design recommendations.

The searchbox should look like a searchbox

Cute attempts to drastically re-style the searchbox usually end in
failure. The universal language of the searchbox consists of a border,
white background, and a corresponding button that says “search.” In
addition to expecting the searchbox to look a certain way, users have
also come to expect it in a particular location: the top right corner of
the page. The further one deviates from this expected appearance and
placement, the more one risks that users will not actually discover the
searchbox.

Provide as-you-type query suggestions

Whether the subject is a particular Icelandic volcano or the president
of Iran, users are often not sure exactly what to type in order to find
what they’re looking for. A little help can go a long way in getting the
user off to the right start. As-you-type query suggestions
reduce spelling errors and, equally important, give users a sense of confidence that they have entered a dependable query.











Autocomplete at Globrix, eBay, and Last.fm

Search results

Assuming that the user found the searchbox and managed to enter a
query, she will then be presented with a set of results matching that
query. Consisting of at least a title and description, search results
are typically dense with information. The challenge becomes separating the signal from the noise.

Indicate the number of results matching the query

The number of matching results has a significant impact on the user’s
confidence in his query. If he sees that a large number of results have
been returned, he can safely assume that his query is adequate, whereas
only a handful of results may be an indicator that he may have
misspelled a word or is simply searching for something that doesn’t
exist.




John Ferrara on Titles

Use descriptive titles

In order for users to detect information scent in search results, the
results must be digestible at a glance. Titles are usually the first
recipients of the user’s attention, so it’s important that they
accurately describe the content that they represent. Avoid using file
names as titles, which are often cryptic and usually contain little
information scent.

Highlight matching words

In addition to descriptive titles, hit highlighting is one of the most
helpful cues on the search results page, making queried words
immediately stand out to the user. The user can quickly evaluate the
list of results by simply observing the greatest concentration of
highlighted words on the page.

Make visited links discernible from unvisited links

A visual indicator of which pages have already been visited provides
useful scent to the user. Whether she is trying to re-find a page she
found yesterday, or trying to avoid duplicating her efforts, a visited
link color is very helpful.




Yahoo's best first pattern

More detail for top results, less detail for the rest

One of Peter Pirolli
’s
interesting discoveries is that users tend to prefer more verbose
results in some circumstances (when there is no time constraint or when
there are few results to choose from), and more concise descriptions at
other times (under a deadline or when there are many results). How can
these opposing cases be reconciled? An ideal compromise is the best first
pattern, in which extensive metadata is presented for the top one to
three results, while more concise views are provided for all of the
subsequent results.

Avoid zero results

A search result page that has no results is a serious roadblock to
users. It will either delay their journey, or cause them to give up
completely. It’s important to do everything possible to avoid zero
result pages from ever occurring. Two helpful tools are automatic
spelling corrections and synonym dictionaries. If the user has obviously
misspelled a word in the query that would yield zero results, it’s best
to automatically correct the spelling for the user, being careful to
notify the user of the modified query.

Faceted navigation

Frequency can be indicated both numerically and with horizontal bars

So the user entered a query and glanced over the first set of
results. What now? If the user already found what he was looking for,
then job done. But chances are he still has a long way to go. Faceted
navigation is the best available tool for facilitating the evolutionary
flow of search. It both helps the user understand
the shape of the data, and gives him the ability to drill down
to a very specific slice of the results.

Show the number of matching results for each filter

Showing result counts for filters helps users understand the overall
composition of the results. They provide cues that feed into our
decision-making process, influencing how we decide to further slice the
data. In addition to providing a numeric count, subtle visual indicators
such as horizontal bars can make the distribution of results even more
immediately obvious to the user.

Use breadcrumbs to indicate the user’s query and applied filters

In addition to choosing where to go next, users need to know where they
are currently and how they got there. Breadcrumbs provide this trail,
and also enable users to quickly get back in the event of having taken a
wrong turn. Each breadcrumb should be independently removable, while Greg Nudelman
has outlined an even more forgiving breadcrumb that allows for the swapping of one filter for a related one.




An internal knowledge management application at British broadcaster ITV

Make metadata clickable

When filterable metadata is shown for a search result, that metadata
should be clickable to allow for organic filtering of the results. For
example, when searching a catalogue of books that presents the author
alongside each result, clicking on the author’s name should cause that
author to be added to the query as a filter.

Find ways to meaningfully visualize facets

Many facets lend themselves to a certain kind of presentation. Whether
the facet consists of cities, prices, keywords or categories, there is
probably a corresponding visualisation well suited for each, from a map
to a slider to plain text. Effective visualisations are ones that make
the data tangible and easy to comprehend.








2010 House of Representative Election from the New York Times, Google Stock Screener

A fairytale ending

Information scent plays a valuable role in making the digital
landscape easier to traverse. By applying principles that amplify
information scent, we can help facilitate a state of flow
that enables users to engage in productive, frictionless, enjoyable search experiences.

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