A-Z indexes: A painful exercise in mindreading

— Published April 28th, 2006  |  by Brian Donohue   |  1 Comments

Lots of people think they like A-Z indexes on websites. Why? They have the allure of simplicity. Users think the index will cut through the confusion and bring them quickly to where they want to go. We’ve come across the issue of A-Z indexes with four of our clients in the last several months. And we say the same thing each time: A-Z indexes almost always stink.

Why they seem like a good idea

We recently conducted a lengthy round of stakeholder interviews for a client whose website has over 4000 page and attracts 4 million visitors per year. To our surprise, in many of the interviews, staff said they thought the A-Z index was one of the most useful parts of the site. (We haven’t reached the user-testing part of the analysis.) The staff just thought A-Z indexes were easier.

Last December, Boxes and Arrows published an article describing the BBC’s major effort to create a site index. (Unfortunately they didn’t discuss the results of the user tests they conducted.) And there are plenty of other articles promoting the unique value of indexes.

What’s the appeal? The author of the above article says the indexes “are the user-friendliest way to search”. And we’ve seen in user tests, people see an A-Z and think “Oh great, that will get to where I want to go right away.”

And then reality hits

Sometimes A-Z indexes can work like a charm. Say you’re looking for when “Sopranos” will be showing, and bang, you can find Sopranos in 5 seconds in the index.

But rarely are things this simple.

What if you’re looking for a report that was recently published by an research institute on healthy eating and specialised diets. What do you look under: eating? healthy? diets? reports? Nope. In this case you’d need to look for “An examination of the cost of healthy eating for a single individual”. The problem of course, is that you need to know exactly what you’re looking for.

And even if you do know the exact title, you have to guess how the indexer decided to list it. This is where you need to quickly polish up on your mindreading skills. What will the site do with articles like "the" and "a"? What if the report actually begins with "Report"? It quite quickly turns into a guessing game. Frustration builds. You begin cursing the designer. Same old story.

So why do people use them?

Interestingly, the BBC includes its index under the title: "Can't find it?" This really says it all.

Jared Spool (who is probably our favourite thinker on matters of the web) suggests that reliance on indexes is a symptom of other problems on a web site, namely the navigation. And I think Jared has nailed it here: People will head for an A-Z when the more standard routes of navigation have failed (though I think he’s wrong to include search in the same category). And sometimes people just assume standard routes will be bad, so they go to the A-Z with an air of naive expectation. Enough time on most A-Z’s will soon cure them of that hope.

But what if you take the time to do it right?

Well, that's what the BBC did with their A-Z index. They poured more resources than most of us ever would to design the index: they were highly selective in what they included, cross-referenced, used synonyms, filed links in multiple places (duplication), and put effort in the visual design. All admirable, yes, and with a good result, in fairness. And as they mention in their article, this is a form of "secondary" navigation for them. They don't expect people to rely on the A-Z.

But this is a massive expense of resources. The bottom line is that most sites'; priority should be to get navigation and search right, and leave out the index. Search, in particular, is frequently poor on sites we work with. And yet it's critical for most sites and surprisingly cheap with offerings like the Google Search Appliance.

Still, though, look for Radiohead in the BBC index and you'll find nothing. But do a search for Radiohead and the first link that comes up is the BBC's profile of the band. Excellent result.

I'll stick with good search any day.