You’re the user experience designer hired in to give shape to a new enterprise search solution. Your client has already decided upon a technology vendor, and has purchased a license. The responsibility now rests with you to provide employees or customers with the best possible information access. Will you design the solution around the assumption that IR algorithms are able to directly deliver the relevant documents in response to most queries, without much further involvement from the user? Or will you design for optimal communication, making the user more responsible for retrieving relevant documents through engaging interaction? Since I don’t believe in technological silver bullets, I argue that good design takes you further for less money when you’re aiming for higher information accessibility.
This post is a continuation of my previous posts on a topology of search concepts, and mediation in information retrieval. I have received a lot of valuable feedback, and one reader commented specifically on my use of the term information accessibility as one of the dimensions for classifying approaches to search. Here’s a snippet from one of the emails I received (reproduced with permission):
When we came up with the definition of accessibility, we also very clearly spoke about the cost required to reach the resource (i.e., user effort to find the document). You would need to compare the costs that users associate with looking through a linear ranked list, versus reading the facet names and then interpreting them and then making a choice and then potentially not finding the document. This across a wide range of potential queries. Only then can you say that one form makes something more accessible than the other.
We were at this point discussing how the definition of accessibility in information retrieval applies to pure best-first (linearly ranked) search vs. faceted search. Put in other words, will a clever ranking algorithm generally provide a shorter path to the document sought by the user, or is the user generally a better judge of relevance? What I’m trying to understand from this discussion as a user experience designer, is how my design considerations may effect the final outcome to the better for businesses and users. I’m also aware that my chain of reasoning does not qualify as proper scientific argumentation.
Technology – What to Reasonably Expect
Many enterprise search customers acquire a search platform for the purpose of implementing search for a web site, an e-commerce portal, or several company systems like email and CRM. Whether the brand is Google, FAST/Microsoft, Autonomy, Endeca or Lucene, these platforms and their ranking algorithms must be tailored to the specific information needs of the company’s employees of customers. If you spent a lot of money on that software license, it’s reasonable to have high expectations for what this magical search box can conjure up. But how much effort will it take to fine-tune the relevance ranking, and can you expect it to perform top-notch across a wide range of potential queries?
There’s little doubt that web search engines like Google, Microsoft Live and Yahoo spend an awful lot of time and money perfecting their ranking algorithms, simply because the credibility of their brands depend on always delivering the best results first. But chances are that your enterprise search client is not able to pour that kind of money into all kinds of relevance trickery. With that in mind, can we reasonably expect ranking algorithms to outperform humans in terms of efficient information seeking? I believe that faceted search holds the upper hand on linear ranked lists (possibly combined with successive query reformation) when accessibility is considered.
Design – How Far Can You Get
I have to admit that I’m partial to set retrieval and faceted search. I believe strongly in solving information seeking problems with good user experience research and design, and have what I like to believe is a healthy skepticism towards technological silver bullets. It’s my experience that some up-front design gives a better return on investment than excessive technical tinkering later on.
A critical step in the design of faceted search is to find meaningful facets that convey a strong scent of information, and the only sure path to well-design facets goes through extensive user research. The set of facets and their values must correspond to the mental model of the users, and it must be immediately understandable to them what results they should expect upon making a selection. Well-designed facets also provide more support to the user as compared to multiple queries / query reformulation, which is more of a guessing game.
When a user reads and interprets the names of facet values, makes a choice and not finds the document he or she was looking for, I think one of 2 things may have happened:
- Either the facets are poorly mapped to the mental model of the user.
- Or the sought-after document simply doesn’t exist.
In the first case, a linear ranked best-first list would’ve been less misleading and would probably have served the user better. That could possibly have provided a shorter path, resulting in higher accessibility. In the second case, the user got early feedback that the search was futile, and that his or her time could be better spent looking somewhere else. In any case, I believe well-designed faceted search is very likely to provide a high level of information accessibility.
A Case of Ingenious vs. Diligent Search?
I have previously written about 4 different approaches to search user experience, where Ingenious and Diligent Search are descriptions of concepts and technologies that bring about high accessibility, with the difference that some are more algorithmically powered, while others are more user powered. I consider the Ingenious approach to include Google’s Universal Search, clustering, LSI, question answering / NLP, search intent analysis and more, where algorithms primarily make the judgment about what is relevant. With the Diligent approach, on the other hand, it’s the user who primarily makes this judgment, which includes concepts like set retrieval and faceted search.
I’m a search user experience designer, and I believe that a well-designed (and possibly low-tech) enterprise search can provide a better return on investment for businesses aiming to provide employees or customers with the best possible information access.









What’s your experience on using multi-level facets versus breaking the other levels down to their own facet list instead? Specifically within the enterprise.
With e-commerce it’s easier to see it used, especially for product group navigation.
Hi Mikael!
First of all I would avoid the mistake of forcing facets into a hierarchy if they’re not hierarchical “by nature”. Hierarchies are best applied when they express a clear is-a relationship between the levels, like in the product group / department navigation on Amazon. If selecting multiple values at each level of the hierarchy, separate into several flat lists.
Secondly, I personally have a dislike towards dynamical expand/collapse javascript trees. Sure, it reminds us of the Explorer interface for browsing Windows file systems, but for the most I think this kind of interaction is unnecessarily complicated. I prefer hierarchical facets where one level is selected at a time.
Some organizations may have established a very complex topic hierarchy that they want to use for faceted navigation. If this hierarchy is either too deep and/or too wide, it’s easy for the user to get lost, or to feel overwhelmed by the number of options. If that’s the case, I would try to persuade the organization to simplify the hierarchy they choose to expose to the users. If you understand Norwegian, have a look at the slightly overwhelming “Tema” site search navigation on http://www.regjeringen.no/nb/sok.html?quicksearch=EU
Another problem with topical hierarchical facets is that the facet values tend to be either too general or too specific, providing the user with little information scent. It that’s not the case, you may still have a problem with the facet value language not matching the users’ mental models.
In short, I prefer to keep it simple. I generally recommend flat lists, unless there’s a clear meaning to the hierarchy. In the latter case I prefer to avoid expandable/collapsible trees.
Perhaps you want to read more about designing for faceted search and backwards highlighting.
Cheers!
I am very interested in where you’re going here, and am looking forward to learning more. Do you have any facilities for testing search, as an A/B live test or log analysis or an academic-style usability test?
The problem with the word “accessibility” is that it’s widely used on the Net for screen readers and other aides for vision-impaired users.
I think that “relevance” is also a loaded and complex term, but at least it’s *our* term, instantly recognizable as search related.
Looking forward to more,
Avi
Vegard, I agree with your view on hierarchical facets
I often find them being too complicated for the user. Just wanted your two cents on the matter.
I know the solution at regjeringen.no fairly well and the navigation is made from a topic map and it shows
Being a technologist I find it fun that search is all about user experience, and not so much about the engine which drives it. A fact often forgotten when a company purchase a specific solution from a vendor.
@Avi Rappoport
Accessibility in information retrieval is the work of Azzopardi and Vinay. It’s very inspirational, but I haven’t taken the time to dig into all the formulas. And yes, accessibility is kind of reserved already, and we should perhaps not use it in this context to avoid confusion.
Relevance is also a very technical terms, and I have lately started using “Best Match” as more user-friendly label for result sorting etc. How do you feel about that?
I haven’t got any tools for testing etc. to share, unfortunately. I mostly do informal user testing with paper prototypes. And I guess you’re already familiar with the writings of Lee Romero and Louis Rosenfeld on site search analytics. Other readers may want to check out these great search log analytics resources:
@Mikael Svenson
You’re welcome
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