four or five levels, they may simply give up and leave your web site. At the very least, they'll become frustrated.
For new web sites and intranets that are expected to grow, you should lean towards a broad and shallow rather than narrow and deep hierarchy. This approach allows for the addition of content without major restructuring. It is less problematic to add items to secondary levels of the hierarchy than to the main page, for a couple of reasons. First, the main page serves as the most prominent and important navigation interface for users. Changes to this page can really hurt the mental model they have formed of the web site over time. Second, because of its prominence and importance, companies tend to spend lots of care (and money) on the graphic design and layout of the main page. Changes to the main page can be more time consuming and expensive than changes to secondary pages.
Finally, when designing organization structures, you should not become trapped by the hierarchical model. Certain content areas will invite a database or hypertext-based approach. The hierarchy is a good place to begin, but is only one component in a cohesive organization system.
3.2.2.3 Hypertext
Hypertext is a relatively new and highly nonlinear way of structuring information. A hypertext system involves two primary types of components: the items or chunks of information which are to be linked, and the links between those chunks. These components can form hypermedia systems that connect text, data, image, video, and audio chunks. Hypertext chunks can be connected hierarchically, non-hierarchically, or both (see Figure 3-12).
3.12. In hypertext systems, content chunks are connected via links in a loose web of relationships.
Although this organization structure provides you with great flexibility, it presents substantial potential for complexity and user confusion. As users navigate through highly hypertextual web sites, it is easy for them to get lost. It's as if they are thrown into a forest and are bouncing from tree to tree, trying to understand the lay of the land. They simply can't create a mental model of the site organization. Without context, users can quickly become overwhelmed and frustrated. In addition, hypertextual links are often personal in nature. The relationships that one person sees between content items may not be apparent to others.
For these reasons, hypertext is rarely a good candidate for the primary organization structure. Rather, hypertext can be used to complement structures based upon the hierarchical or database models. Hypertext allows for useful and creative relationships between items and areas in the hierarchy. It usually makes sense to first design the information hierarchy and then to identify ways in which hypertext can complement the hierarchy.
3.2.2.4 The relational database model: A bottom-up approach
Most of us are familiar with databases. In fact, our names, addresses, and other personal information are included in more databases than we care to imagine. A database is a collection of records. Each record has a number of associated fields. For example, a customer database may have one record per customer. Each record may include fields such as customer name, street address, city, state, ZIP code, and phone number. The database enables users to search for a particular customer or to search for all users with a specific ZIP code. This powerful field-specific searching is a major advantage of the database model. Additionally, content management is substantially easier with a database than without. Databases can be designed to support time-saving features such as global search and replace and data validation. They can also facilitate distributed content management, employing security measures and version control systems that allow many people to modify content without stepping on each others' toes.
Finally, databases enable you to repurpose the same content in multiple forms and formats for different audiences. For example, an audience-oriented approach might benefit from a context-sensitive navigation scheme in which each audience has unique navigation options (such as returning to the main page of that audience area). Without a database, you might need to create a separate version of each HTML page that has content shared across multiple audiences. This is a production and maintenance nightmare! In another scenario, you might want to publish the same content to your web site, to a printed brochure, and to a CD- ROM. The database approach supports this flexibility.
However, the database model has limitations. The records must follow rigid rules. Within a particular record type, each record must have the same fields, and within each field, the formatting rules must be applied consistently across records. This highly structured approach does not work well with the heterogeneous content of many web sites. Also, technically it's not easy to place the entire contents (including text, graphics, and hypertext links) of every HTML page into a database. Such an approach can be very expensive and time consuming.
For these reasons, the database model is best applied to subsites or collections of structured, homogeneous information within a broader web site. For example, staff directories, news release archives, and product catalogs are excellent candidates for the database model.