If customers get the first click right they have twice as much of a chance of completing their task than if they get it wrong.
Nobody likes taking a wrong turn, particularly when it's your first turn. If you have travelled 10 kilometers in the wrong direction, then it feels like you are travelling back 20 kilometers.
Linking is the foundation of the Web. It is its key distinguishing characteristic. It is what makes the Web the Web. The essence of linking is navigation. The essence of navigation is helping someone get someplace. A link is a signpost, a promise.
That most important skill by far that any web professional can have is link design. The most important aspect-by far-of link design is the choice of words.
A 2010 study by Webusability found that, "participants were about twice as likely to succeed if they selected the correct response on the first page with which they had to deal … In addition, those scenarios that had incorrect first clicks tended to take longer to complete, and required more page views."
Commenting on the study, Measuring Usability stated that "Few things affect task success more than the navigation of the website. If users can't find what they're looking for, not much else matters."
Another research paper, published in 2011, states that when people are on the Web, "The main attention is paid to the starting and ending documents. They should be designed well."
You can't have good search if you don't have good navigation. The quality of search results is directly dependent on the quality of the navigation. The better structured the environment, the better the search results will be.
The best navigation is focused on top tasks. The best navigation is simple. It has as few choices as possible. Thus, you must focus on the highest demand tasks (top tasks). Great navigation is exclusive. Each link is absolutely separate and distinct.
Let's say you have a support problem. You see these links: FAQs, Tools, Resources. Which one should you choose? This is an example of the most basic mistake in navigation design: overlapping links.
Design the top level of your navigation in isolation. Base it on your top 20 tasks. Then test it with about 20 top task questions. Ask a minimum of 20 people what their first click would be based on the navigation you present them. You can do this manually using the simplest of wireframes. However, the simplest way we've found of doing this is by using Optimal Sort from Optimal Workshop.
Aim for a 90 percent first click success rate. Keep tweaking your navigation until you get that success rate. Design downwards. Get the first level right then work on the second level. Measure the success of your design based on task success. Most of what you will be doing to improve success rate will involve changing words.