Note that I used the plural — not map, but maps. Librarians actually have a variety of information maps. They're kind of like those anatomy illustrations in an encyclopedia, with multiple see-through plastic overlays that one can superimpose on the outline of the human form. Which map we use will be determined by the kind of questions we're answering.

Why is it worth identifying our mental maps and thinking about them? To remind ourselves when we get bogged down in a question, that we can reorient ourselves to a different map and a different strategy for finding answers.
 

Mapping Our Own Library
Since we've all played a role in building our collections and worked with them for a long time, most of us start the process of answering questions with what is right at hand within our building (though some of the younger, technology-savvy librarians may tend to go directly to the Internet and only use our collections when that strategy fails).

Our mental map of our collection probably combines areas and functions, perhaps something like the one in Mental Map # 1 above.

A map like this has one major problem. Sometimes we don't remember that information overlaps those categories. We may end up restricting ourselves to only one or two parts, like the reference collection and the stacks.

How many of us who are not government documents librarians remember to think of government documents as possible answers? When someone wants to know about college dance programs, how many of us realize that Dance Magazine is a valuable source? How many of us, given a how-to-do-it question, remember to look for videos? How many of us looking for images remember that the children's collection is a great source for pictures? (Long ago, when someone needed a picture of the clown Emmett Kelley and the usual reference sources weren't panning out, I headed to the children's room for Robert Quackenbush's book about him, The Man on the Flying Trapeze, which I had just read to my 3-year old.)
 

Mapping by Call Number
But we also have detailed maps of the collections we use every day. We map by call number, for instance, by physical location. Which of us can not be rendered totally disoriented by a collection shift, because we always used to go there for the quote books, and the books aren't there anymore. Perhaps that's why some of us have committed entire classification schemes to memory. I know that if I ever go on Jeopardy, I will chose LC call numbers for my category (see Figure 1 on page 45).
 

Mapping by Type of Reference Source
We may also map by format: A "Where is it?" question calls for an atlas or gazetteer, while a "How many?" question cries out for a statistical source, and so forth. In fact, when I did graduate work at the University of Iowa, its library's reference collection was not arranged in straight Library of Congress call-number order, but was divided into alcoves by reference type: the bibliography alcove, the biographical alcove, the statistical alcove; books were secondarily arranged by call number within those alcoves and reference types (see Figure 2 on page 46).
 

Mapping the Local Information Community
We also have mental maps of our local information community. We know the specialties and resource strengths of other libraries in our area. My mental map of Quad-Cities information resources, for instance, includes genealogy materials at the county historical societies, Davenport Public Library and Rock Island Public Library, an agricultural collection at John Deere's library, medical collections at local hospital libraries and Palmer College of Chiropractic, city and county government records, and the morgues of three local newspapers. My map also includes my mental rolodex of local subject experts: for instance, a priest who can translate Latin; a craftsman who builds kaleidoscopes and knows everything about their history; a long-time union official who has the entire history of Quad City labor conflicts stored in his head; and the county extension agent who can identify weeds and pests. See my Mental Map # 2 on page 46.
 

Mapping by Likely Suspect
Another type of mental map builds around asking who might logically generate, gather, and preserve that sort of information. When we need official information of any kind, we look for the relevant government agencies. When we need environmental data, we may think of both the Environmental Protection Agency and the Sierra Club. When we need statistics on industry, we may look for data from both the Department of Commerce and trade associations, but when we need data on what people think about anything, we may look for polls, letters to the editor, and maybe communal Weblogs like Metafilter or consumer complaint centers like E-Opinion. When we want data about who buys what and why, we look to business and trade organizations for market surveys. When we want to know what life was like for ordinary people at a certain point in history, we think about books, diaries, letters, and old magazines and newspapers. When we want research, we think of individual scholars, dissertations, scholarly journals, and electronic databases. See my Mental Map # 3 on page 46.
 

Topographical Maps of the Features of the Information Landscapes
We also have a kind of topographical map of information, a sense of the specific information properties of each landmark.

When do we head for books? When people don't need primary resources and do want a lot of background, history, analysis, and recommendations for further reading, all in one compact package.

When do we head for magazines and newspapers? When people want something current, easily readable, targeted at particular interests (Cat Fancy, Model Railroader), illustrated with both pictures and advertising (if you need a picture of a tractor, head to Successful Farming), and often with special supplements (the U.S. News best colleges issue, Library Journal's architectural issue).

When do we head for government documents? When we want something official. When we want statistics, grants, laws, court cases, expert testimony from congressional hearings, and the kinds of research required by law (environmental impact statements, accident investigations, criminal profiles, etc.)

When do we turn to AV material and all the images on the Web? When someone asks us "What does a blue jay look like? What does it sound like?" or "Here's a picture of this snake that lives under my house. What is it? Is it poisonous?" or "How do I cast on stitches?"

We look to the Web for the things it does really well: for images, animations, and sound files, for current news, for online government documents, for interactive learning (diagnose and prescribe treatment for patients from case files and find out if you saved them or killed them), for online discussions and chat with like-minded people. Above all, we go to the Net for 24/7 accessibility, and for searchable texts. When I want to find what rock performer sang, "I'm going to raise my son to be a prophet of mistakes," I head to the Net.

We also get searchability and 24/7 access with databases, but we also pay for, and get, authority; we go there when we want some guarantee of trustworthiness. After all, nobody publishes an article without at least one editor critiquing and correcting it.

We look to organizations — the American Heart Association, the American Kennel Club, the Red Cross, etc. — for free information about their mission; we expect them to provide current news about their issues, experts who will answer your questions, archived research, perhaps a trade magazine, perhaps a bulletin board or discussion forum.

We look to individuals, too. Sometimes for expert knowledge, sometimes to share ideas, and sometimes for comfort and wisdom. We may find them on the Web, in individual or shared Web pages and Weblogs. We may find them in chat rooms or Usenet groups or support groups. Librarians need to remember to steer patients to support groups as well as medical information, because the best doctors in the world still can't tell you what it feels like to have that medical condition, whether it's normal to spend the next 24 hours throwing up after taking a medication, and how to handle not only the disease, but its effects on your family life as well (see Mental Map #4 on page 46).
 

Guided Tour or EuroRail Map? Mapping What Kind of Question Requires What Kind of Search
I think there's one more mental map, and it dictates how we go about our search. In some situations, we might choose to look through classified subject directories, in catalogs or Internet portals, or specialized indexes; in others, we might prefer a more free-form, keyword-based search, through general databases or Internet Web sites or discussion groups.

We may base our choice on whether we want to access either a limited body of knowledge, selected and ratified by authorities in the field, or a wider-ranging universe that includes ideas and research not yet accepted but possibly valid.

But we may also base our choice on whether we want to investigate a subject systematically, studying known relationships within a subject area, or whether we seek entirely unknown and unexpected relationships between that subject and others.

For instance, if you wanted to study Protestantism in a thorough and systematic way, you could just read your way through in Library of Congress order:

BX 4800-9999 Protestantism

BX4800-4861 General

BX5011-5207 Church of England

BX6101-9999 Other Protestant Denominations

BX6201-6495 Baptists

BX8001-8080 Lutherans

BX8201-8495 Methodists

BX8601-8695 Mormons

BX8901-9225 Presbyterians

But some topics leak across disciplinary boundaries — an exploration of the effects of Protestantism on political philosophy, for example, or the contributions of Mormons to the arts — and require a more adventurous approach.

For topics like these, librarians will more likely look for clues by doing keyword searches through wider universes — the Web, WorldCat, Dissertation Abstracts, and such. We might take known writers on the topic and do a citation search on them, which can take us in entirely unexpected directions. (Did you know that a citation study on Albert Einstein leads to an article in a journal of dairy science?).

It is your mental map that tells you whether the structured systematic search or the Weblike, collage-building search is most appropriate.
 

Follow Me!
These are my mental maps, and many of you may share at least some of them. On the other hand, you also have your own mental maps, ideas about the information landscape that haven't occurred to me.

The point of this article is to challenge you to identify what those maps are, think about how and when you apply them, and remind yourself that you may solve an information problem by switching from a mental map that's not working to an entirely different one.