Jakob Nielsen and Kara Pernice Coyne
It's crucial for websites to provide search interfaces that are
available, simple, and productive. This article gives basic
instructions about how to test your website's search interface
for usability.
We recently assessed the usability of twenty ecommerce sites: ten
of the world's highest-grossing sites and ten other sites that
sell the same kinds of products, but have substantially smaller
revenues. The ten high-selling sites complied with 40% of our
usability guidelines for search whereas the ten less-selling sites
only scored 27%. Even the best sites on the Web are far from
having perfect search, but it is still remarkable to note the
difference in search quality between sites that sell well and
sites that sell poorly. Of course, rule #1 of ecommerce is: if
the user cannot find the product, then the user cannot buy the
product. Thus, the findings in our study are very understandable.
Get more information about the study at:
http://www.nngroup.com/reports/ecommerce
Search is something most people try to use on websites. Some
people simply prefer it to browsing. Others like to browse but
are driven to using search when browsing does not help them find
what they want. Often the information on websites is organized in
categories, and the user does not know which category a particular
item is under. The site designer may have a logical structure in
mind, but the arrangement still might not help the user. For
example, a person wants to buy a Lenny Kravitz CD for his nephew
but he does not know what type of music Lenny plays. He might try
browsing a music site and looking in the classical or country
categories. He wouldn't find the CD there. He would probably
resort to searching the site for the artist's name, or possibly a
song title or album name if he knew it. If that didn't work, it's
likely that the shopper would leave the site and go to another
one to make the purchase. To avoid this catastrophe, web
designers can conduct basic usability studies to help them learn
how to improve their search usability.
Steps in a Basic Usability Study
Usability studies can be elaborate or basic. Even 30 minutes in a
cubicle with paper and a pencil can be effective. When looking for
quick feedback about a search interface, your study should include
the following steps:
1) Determine the goals of the study
2) Determine the user profile and schedule the sessions
3) Write the user's tasks
4) Conduct the sessions
5) Evaluate the data
6) Implement changes, and repeat steps one through seven as long
as the site exists
Determine the Goals of the Study
Decide on some clear, concise goals for the study. For example:
Learn what is easy or difficult about constructing a search. Or,
learn what is easy or difficult about using search results. Keep
these goals in mind when writing the user tasks.
Determine the User Profile and Schedule the Sessions
The people who test the interface should absolutely have similar
experience levels as those who will use the live site. Decide what
traits are pertinent, for example: web experience, search
experience, occupation, age, experience using competitive sites
or the site you are testing.
Be prepared to offer an appropriate incentive. Some popular
honorariums include cash or a check (often $100 US), sweatshirt,
software, pens adorned with a product name.
Write the User's Tasks
While there are many steps and features involved in searching,
there are a few basic things people should be able to do, and
that you should try to include in your user tasks.
1) Find the search interface: Do not bury it.
2) Type words, create search string: Search should accept and
understand both natural language and Boolean strings. You will
probably find that most users simply type a single keyword or at
most two or three words. Complex queries are rare on most sites.
3) Invoke the search: Provide a clearly-labeled button near the
query entry field. People expect the Enter key to work too.
4) View, use, and understand the results: The user needs to know
where the results are, not buried in categories or advertising,
and which results are the most relevant. Also, opening and
reading the pages or documents should be straightforward.
5) Refine or narrow the results.
In the tasks you would give the users, you would not actually use
the above words. On the contrary, these are just parts of the
bigger user task or goal to "get the information I want," or "buy
Mom a birthday present."
During usability sessions, we often give users a protocol or set
of tasks to follow. Writing the tasks is more of an art than a
science. The idea is to give people enough information without
guiding them to the solution. Tell them things they should try
to accomplish that are realistic and might occur in a real-life
scenario. For example, one task might be: Get your mother a
birthday present. In this task you don't use the word search,
you don't tell them any product names, you don't tell them to
deal with results or relevance rankings. You leave it open-ended
for the user to decide what Mom would like, and how they will
find it. Then, you watch them try to get the work done, and
analyze their behavior as they do.
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