Understanding How Users Search
Assuming you've decided to implement a
searching system for your web site, it's important to understand how users
really search before designing it. We'll try to condense decades of research
and experience generated by the field of information retrieval into the next
few paragraphs. But it really boils down to this point: searching systems can
and should vary as much as browsing systems or any other components of web
sites do, because all users aren't alike, and information retrieval is much
harder than most people realize.
1. Users Have Different Kinds of Information Needs
Information scientists and librarians have
been studying users' information finding habits for decades. Until recently,
these studies usually pertained to traditional information systems, such as how
to ask a library patron the right questions to learn their information needs,
or how to make it easier to search for information in online library card
catalogs or other databases.
Many studies indicated that users of
information systems aren't members of a single-minded monolithic audience who
want the same kinds of information delivered in the same ways. Some want just a
little information, while others want detailed assessments of everything there
is to know about a topic. Some want only the most accurate, highest quality
information, while others don't care much about the reliability of the source.
Some will wait for the results, while others need the information yesterday.
Some are just plain happy to get any information at all, regardless of how much
relevant stuff they're really missing. Users' needs and expectations vary
widely, and so the information systems that serve them must recognize,
distinguish, and accommodate these different needs.
To illustrate, let's look at one of these
factors in greater detail: the variability in users' searching expectations.
1.1. Known-item searching
Some users' information needs are clearly
defined and have a single, correct answer. When you check the newspaper to see
how your stock in Amalgamated Shoelace and Aglet is doing (especially since the
hostile Microsoft takeover attempt), you know exactly what you want, that the
information exists, and where it can be found. This is the simplest type of
information need. If it were the only type, the job of the web site architect
would be much easier.
1.2 Existence searching
However, some users know what they want but
don't know how to describe it or whether the answer exists at all. For example,
you might want to buy shares in a particular type of mutual fund that invests
in Moldovan high-tech start-ups and that carries no load. You are convinced
that this sector is up-and-coming, but do Fidelity and Merrill Lynch know this
as well? You might check their web sites, call a broker or two, or ask your
in-the-know aunt. This kind of information need is more challenging: it might
be hard to convey exactly what you're looking for ("Moldova? What's
that?"), especially if it's a new and as-yet-unheard-of item. Rather than
a clear question for which a right answer exists, you have an abstract idea or
concept, and you don't know whether matching information exists. The success of
your search depends as much upon the abilities of the brokers, the web sites, and
your aunt to understand your idea and
its context as whether the information (in this case, a particular mutual fund)
1.3 Exploratory searching
Some users know how to phrase their question,
but don't know exactly what they're hoping to find, and are really just
exploring and trying to learn more. If you ever considered changing careers,
you know what we mean: you're not sure that you definitely want to switch to a
career in chinchilla farming, but you've heard it's the place to be, so you might
informally ask a friend of a friend who has an uncle in the business. Or you
call the public library to see if there's a book on the subject. Or you write
to the Chinchilla Professionals' Association requesting more information. In
any case, you are not sure exactly what you'll uncover, but you're willing to
take the time to learn more. Like existence searching, you have not so much a
question seeking an answer as much as an idea that you want to learn more
about. Unlike the next type of searching, you don't need to know everything
there is; a few pieces of good information will do fine for now.
1.4 Comprehensive searching (research)
Some users want everything available on a
given topic. Scientific researchers, patent lawyers, doctoral students trying
to find unique and original dissertation topics, and fans of any sort fit into
this category. For example, if you idolize that late great music duo Milli
Vanilli, you'll want to see everything that has anything to do with them -
singles and records, bootlegs, concert tour posters, music videos, reviews, fan
club information, paraphernalia, interviews, books, scholarly articles, and
record-burning schedules. Even casual mentions of the band, such as someone's
incoherent ramblings in a web page or Usenet newsgroup, are fair game if you're
seeking all there is to know about Milli Vanilli. So you might turn to all
sorts of information sources for help: friends, the library, bookstores, music
stores, radio call-in shows, Ouija boards, and so on.
There are many other ways of classifying
information needs, but the important thing to remember is that not all users
are looking for the same thing. Ideally, you should anticipate the most common
types of needs that your site's users will have and ensure that these needs are
met. Minimally, you should give some thought to the variations and try to
design a search interface that is flexible in responding to them.
2. Searching and Browsing Are Integrated
One drawback to the literature on information
finding is that much of it deals with testing and improving a single
information system (e.g., an online card catalog). But the truth is that most
people, especially those with more involved information needs, use many
information systems for a particular search. This often means jumping from
Infoseek to Magellan to a specific site to Hotbot and so on, all in the context
of one search. Even when using a single web site, users often alternate between
browsing and searching. For example, when you use Yahoo!, you might first
perform a search, find a useful site, and then, using its Yahoo! category,
browse for similarly indexed sites.
3. Multiple Iterations Are Commonplace
Additionally, information searching generally
doesn't take place within one clean pass, unless it's of the known-item searching variety.
Information searching and browsing are by nature iterat ive : users will make
a first attempt at finding information, learn something, refine their
query, try finding some more, learn some more, refine again. This is commonly
known as associative learning .
Unfortunately, finding everything you need at once doesn't happen all that
often, because you don't generally know enough about the topic to articulate
your query the right way in the first place.
4. The Moving Target: A Likely Scenario
A typical example of a search for information
might go something like this:
a budding entrepreneur, wants to get business cards printed for her new
company. She calls her pal Fred to see how he did it and what company he used.
Unfortunately, Fred is not in, and, never one to dawdle, Jan leaves Fred voice
mail and moves on to the yellow pages. She finds nothing under Business Cards,
but does see a number of companies listed under Printers, and gets a few price
quotes, which all seem to be in the same neighborhood. Not sure which to
select, Jan contacts the local chapter of the Better Business Bureau for their
recommendation. The BBB folks refer Jan to their web site, where she can search
a database of companies with dubious histories. This provides Jan with useful
information that helps whittle down her list of candidate printers. Meanwhile,
Fred calls Jan back and tells her that she really shouldn't have just business
cards printed, but that she should hire a graphic designer to create a full
graphic identity package for Jan's new business, including letterhead,
brochures, and so on. So, Jan realizes that she needs to find an affordable,
reputable graphic design firm, and she returns to the yellow pages. She also
goes to the library to do a catalog search to see if any books describe what
it's like to work with a graphic design firm, and how much she ought to expect
to pay. And so on...
As you can see, Jan's initially simple
information need becomes a fully fledged associative learning process, changing
at least twice (from a hunt for a printer to a hunt for a graphic design firm
to information on negotiating and working with a graphic designer), and for all
we know, it's not over yet. It also involves multiple information sources (Fred, the yellow pages, the library
catalog, the bookstore), and utilizes
browsing (the yellow pages directory),
searching (the Web database, the library catalog), and even asking (Fred, the Better Business
Bureau). Things aren't always as simple as they seem! Your challenge, of
course, is to design your site's architecture to support the most common
searching and browsing approaches in a smooth and integrated way.