Landmarks are distinctive and should be easily visible for some distance.

Routes are somewhat abstract -- although the person using a familiar route knows where to turn and how far to go, she may not pay attention to the specific features of the landscape along the way and may not be able to tell someone else the actual names of the streets or buildings where critical turns should be made. A route navigator who misses one turn is well and truly lost.

Maps reveal overall spatial orientation and the general relationships of one place to another. Most of the time there is more than one way to get to a certain destination, and a map allows the traveler to adjust his route many times while still moving efficiently toward that destination.

McKnight, Dillon and Richardson (1993) summarizes the three primary ways people use to find their way around in the real world as a progression. Some people use only the first, most basic method -- landmark navigation -- and do not progress to the others. Some people (statistically more men) progress through all three and use primarily map navigation. More women than men use route navigation.

Landmark ... in this type of navigation, people choose a readily-identifiable feature of the general landscape and use it as a base. They move out from the base to explore, returning to the base whenever they get lost or whenever they want to start over and explore in a different direction. When they become familiar with an area, they may move from one landmark to another in order to navigation through larger spaces. Many people find themselves using this navigation method when they are visiting strange cities -- leaving the hotel and taking note of a prominent building nearby so they can find their way back!

Route ... in this type of navigation, people learn routes between one location and another, or sometimes between one location and several others. If you are a route navigator, or you know one, you will be familiar with the phenomenon of driving to the grocery store and then having to drive back home in order to get to the movie theater because the driver does not know a route directly from  the grocery store and the movie theater. Route navigators tend to learn many familiar routes and then connect these, or use their intersections, to navigate to places for which a route has not yet been learned.

Map ... in this type of navigation, people form a mental map of the space in which their moving and use it to direct themselves via spatial relationships rather than landmarks or routes. If you are with a driver who says, "When I visited here two years ago I remember the hotel was in the southeast corner of the downtown square -- we'll just head that way until we find it," you are probably with a map navigator.

NOTE: All kinds of navigators can use actual printed maps, but they will use them in different ways. Landmark navigators may look for big intersections or features like parks and public building that they recognize. Route navigators may search the street index to identify a part of a route they know and go from there to trace the route they need. Map navigators may study the map to ensure their mental orientation is accurate, then fold the map and steer happily in the right direction.

• Where am I now?
• Where can I go from here? What can I do here?
• How do I get back to where I was?
• How do I get out of here?

While there are plenty of considerations to take into account when you embark on navigation design, if you look at each of the displays in your product as if you had to answer all the questions above, you will be addressing the most important aspects of navigation.

Remember that human beings are conservative with our cognitive processing resources -- when you answer these questions for me, do so in a consistent way and in consistent locations on the display. It's no good if the answers are there but keep changing places so that I have to hunt for them every time I move to a new display!

In addition, Carroll (1999) points out that people try to apply their prior knowledge to new situations, so if you begin to use navigation signals in ways that look the same but act differently than ones that people are used to (like underlined text, especially blue underlined text, on the web that does not actually go anywhere!), they will apply their prior knowledge and get very frustrated. (Note: the link in this paragraph does not go anywhere. It is there to illustrate how infuriating it is when you expect blue, underlined text to be a link based on your prior experience and then to find blue, underlined text that is not a link!Come on -- admit that when you see that text up there you thing you really should be able to click it and get to another page -- don't you?)

But this is such dumb, basic stuff -- would any designer actually make this kind of mistake? Yes. I've seen products in which the text was blue to match some overall color scheme, and then the author used underlining to identify books titles or to emphasize phrases. Of course, those designers didn't set out to make such a bone-headed mistake; they made a series of decisions and never stepped back to look at the overall product with the simple, basic ideas in mind. Other designers simply do not spend enough time looking around the world at other designs so they make mistakes because they don't realize what the experiences of their audiences have been.

Keep in mind the human interaction question as well. Have you ever walked into a store or another kind of establishment in which someone appeared to direct you around and then never left you alone?

"May I show you this?"
" Would you like to try that on?"
" We have one of those in green if you'd be interested ..."

After awhile the "help" is more bothersome than any amount of confusion might have been. People don't want to have to notice the answers to their navigation questions until they need those answers. So keep them consistent and keep them low-key.

Sometimes more is better. If you have a large product, representing the scope of it through your navigational cues can be helpful. People realize they should be cautious, and they appreciate not having to traipse down a couple dozen link paths to figure out what is there.

More is not always better. When people are anxious, or when they are concentrating on something besides your navigation structure (possibly on your content!), their powers of interpretation and especially of observation diminish markedly. Even people with a lot of expertise in the subject matter and decent technology skills are subject to confusion and oversight when they are studying intently - which is what you often hope they are doing with your painstakingly designed instruction! The more complicated your content gets, the more care you should take to simplify the navigation required for people to use it.

How could someone possibly have trouble with my dinky little online lesson? Yes. Someone can have trouble with a small product as well as with a large one -- and very often that trouble has to do with navigation. Did you ever start reading on a bus and look up to realize you had missed your stop? Have you ever been listening intently to a news item on the radio in your car and suddenly realized you aren't sure where you are or how to get back to the right intersection? How about missing a turn while you were talking to a friend in the car?

Sometimes designers who work with a lot of technology suspect that people who have trouble with navigation may be -- well, let's face it -- too lazy or unmotivated to figure out even the simplest little thing. We tend to forget the situations in which we have trouble with navigation (department stores? big cities? cornfields? buildings with identical wings on both sides and confusing room numbers?) In those cases we figure the problem is that we don't have time to spend on figuring the thing out or the situation was overwhelming or unfamiliar ... and we are probably right.

Of course, those same problems face our users, and they are generally no more lazy or unmotivated than we are. If they are equally lazy and unmotivated, they have the same good reasons for it that we do.

If you concentrate on creating a consistent structure that helps people know at any given time where they are, where they can go, how to get back, and how to get out -- you will be creating a strong foundation for your product. A strong foundation can make up for many, many smaller problems with color choices, image selection and other difficult design areas.

Web Navigation is probably the most comprehensive book you can get on designing navigation ... it's not just another HTML tutorial masquerading as a design book. Fleming addresses the big issues (including the big questions users ask) in a straightforward and helpful way.

Underhill, P. (1999).Why we buy. New York, NY: Simon and Schuster. (May get for $11.00 at www.half.com, or as low as $8.00 in amazon's used market.) Read this book for an in-depth, and empirically-based discussion of how people navigate in a particular subset of physical space -- the point of view in this book is analogous to the one that media designers should be taking.

Boling, E., King, K., Avers, D., Hsu, Y., Lee, J. & Frick, T. (1996). Navigating backward: Concrete vs. abstract representation in hypertext buttons. Canadian Journal of Educational Communication, v25, n2, pp. 161-176.

Carroll, J. (Ed.). (1998). Minimalism beyond the Nurnberg funnel. Cambridge, MA: MIT Press.