June 1999 Navigation By Michael A. Trick INFORMS Online (IOL) currently consists of approximately 20,000 Web pages. This number is somewhat overstated since we used to have a separate Web page for every conference presentation; we now only go down to the session level. Still, there are thousands of pages that people are consistently looking at. Providing an easy and intuitive way to get to all of those pages is key to the design of IOL. The choices we have made illustrate the wide variety of navigational items that can be used on Web pages today. IOL has grown organically over the four years of its life. Periodically, the associate editors and I revamp its design in order to make it easier to use. The basic structure of IOL has remained consistent: There are about 12 major categories (Publications, Conferences, and so on) and all pages fall within one of the categories. The navigation within a category and between categories has changed a lot over the last few years: At some point or another, we have tried most methods for easing the difficulty of traversing thousands of pages. Here are some of the things we have used: Clickable graphics: Graphics provide an appealing way to present a small amount of material. Many graphics at IOL can also be "clicked on" to navigate to the subject of the graphic. The most obvious example is the "informs" graphic itself. Clicking on it will always bring you to the main page. This very obvious setup means that no one can ever get "dead-ended" at IOL: You are always one click away from the home page. We also use "banner graphics" at the top of the main page. Since the main page gets hit far more than any other page (about 10,000 times per week), the top of that page is prime territory. We generally put a graphic there to alert visitors to conference deadlines, new services or important news. Clicking on the graphic then leads to more detailed information. Imagemaps: An imagemap is a graphic designed for navigation. Clicking on different parts of the imagemap will take you to different parts of IOL. We have just one imagemap at IOL, but it is an important one: On the main page, there is a graphic that allows immediate access to each of the 12 areas. There are two types of imagemaps: server side, where the machine hosting IOL interprets clicks, and client side, where the machine hosting the browser interprets hits. Since we use a client-side imagemap (by far the more popular choice due to its decreased load on the server), I cannot tell how often the imagemap is used, but it seems a popular choice when I watch people use IOL. Thanks go to the former president of INFORMS, Art Geoffrion, and his assistants for putting together the imagemap, and generally encouraging the navigational redesign of IOL. Javascript Navigation: One disadvantage of imagemaps is that they take up a lot of space. We briefly had the imagemap on every page of IOL. This seemed excessive, and seemed a poor use of limited screen space. Instead, we put in a navigational tool based on Javascript. Javascript is a scripting language that can be used to increase the interactivity of Web pages (Javascript has nothing to do with Java, a fuller language also used on the Web. Not surprising coming from the people who are bringing you the Y2K problem!). At the head of every page at IOL, there is a drop-down menu next to the "informs" graphic. This menu allows direct navigation to any other major part of IOL. This piece of javascript is quite simple, but has some subtleties. For instance, one somewhat non-standard aspect of this script is that you do not need to press a "Go" button after choosing the destination. The script takes you there immediately. Magic! And if you are using an older browser (and it would have to be quite old now) that does not support javascript, a "Go" button automatically appears and the javascript device changes into a different device that every browser can handle. I like this bit of script very much. Like many good things on the Internet, I did not have to create it myself. You can get the directions at http://www.inquiry.com/techtips/js_pro/files/10min0898/10min0898.htm Tables and Sidebars: Perhaps the most common navigational device on the web is the use of "sidebars." Sidebars use the "Table" feature to have a navigational listing running down the left hand side of the web page. We recently reorganized the Publications area http://www.informs.org/Pubs (in preparation for the highly anticipated Electronic Publishing initiative) and decided to include a consistent sidebar in this area. This allows the easy movement from one journal to another. Sidebars take up screen space, but they are fast, attractive and easy to maintain. Search Engines: Though perhaps not commonly thought of as a navigational tool, the search feature at IOL allows users to quickly find pages of interest. Rather than browsing through hundreds or thousands of pages, the search feature puts up a list of relevant pages which can then be accessed directly. Other Devices: We have tried many other things over the years. One approach that did not work well for us is "Frames." Using frames divides the screen space into different rectangles. One area might be used for navigational pointers, another for an advertising banner, and a third for the main screen content. Frames look somewhat like using tables to design pages. You can tell the difference because the areas with frames can scroll independently of each other. Many sites (including the online version of OR/MS Today) use frames successfully to create an intuitive and easily navigatable site. I dislike frames due primarily to difficulties in bookmarking or pointing to individual pages. With frames, there is no address that corresponds to any particular configuration of frame content. Therefore bookmarks and pointers can only go to the "base" configuration of the frames. At IOL we use frames in exactly one place: the "make your own bulletin" feature associated with each conference. There, frames are used to allow simultaneous viewing of session information and selection of items to include in the bulletin. Otherwise, the associate editors know that using frames is the only firing offense at IOL. Michael Trick of the Graduate School of Industrial Administration, Carnegie Mellon University, is the editor of INFORMS Online (http://www.informs.org/). Table of Contents OR/MS Today Home Page OR/MS Today copyright © 1999 by the Institute for Operations Research and the Management Sciences. All rights reserved. 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