Information architecture components can be divided into four categories:
Organization systems – how do we categorize information, for example by subject or date.
Labeling systems – how do we represent information, for example scientific or folk terminology.
Navigation Systems – how do we browse or move through information, for example clicking through a hierarchy.
Searching systems – how do we search information, for example executing a search query against an index.
In my today’s post, I am going to describe organization systems component of information architecture. Organization systems are composed of organization schemes and organization structures.
An organization scheme defines the shared characteristics of content items and influences the logical grouping of those items. An organization structure defines the types of relationships between content items and groups. Organization systems form the foundation for navigation and labeling systems.
There are exact and ambiguous organization schemes.
Exact organization schemes divide information into well defined and mutually exclusive sections. For example, alphabetical order of a phone book. If you know the person’s last name, you can look in that letter of the alphabetical list. This is called known-item searching. You know what you are looking for and it is obvious how to find it. The problem with exact organization schemes is that they require a user to know the specific name of the object they are looking for. Exact organization schemes are easy to design, maintain, and use.
Types of exact organization schemes include alphabetical, chronological, and geographical.
Ambiguous organization schemes divide information into categories that defy exact definition. They are difficult to design and maintain, and they can be difficult to use. Is tomato a vegetable or a fruit? However, they are often more important and useful than exact organization schemes. Why? Because users don’t always know what they are looking for. Information seeking is often iterative and interactive. What you find in the beginning of the search may influence what you look for and find later in your search.
Ambiguous organization supports the method or grouping items in meaningful ways. Therefore, while ambiguous organization schemes require more work, they often are more valuable to the user than exact schemes. The success of these schemes depends of the quality of the scheme and the placement of items within this scheme. User testing is very important for this type of scheme. There is ongoing need for classifying new items and for modifying the organization scheme to reflect changes in the scheme.
Types of ambiguous schemes include are topic or subject, task, audience, metaphor, hybrids.
Topical schemes organize content into subjects.
Task scheme organize content by processes, functions, or tasks. Most common example of web sites using this scheme is e-commerce sites where a user interaction is centered on tasks, for example buy, sell, pay, etc.
Audience oriented schemes are useful for sites that are frequented by repeat visitors of a certain audience. For example, Dell web site separates its content into "Home" and "Business". Audience schemes can be open or closed. An open scheme would allow users of one audience to access content or another audience. A closed scheme would prevent users from using content of another audience.
Metaphor schemes use association with known subjects. They should be used with caution. They must be familiar to users.
Hybrids combine elements of multiple schemes.
The structure of information defines the ways in which users can navigate. Major structures are hierarchy, the database-oriented model, and hypertext.
The foundation of almost all good information architecture is a well designed hierarchy or taxonomy. In creating a taxonomy, it is important to not make categories mutually exclusive. You need to balance between exclusivity and inclusivity. Sometimes an item may belong in more than one place. It is also important to balance between breadth and depth in the taxonomy. Breadth refers to the number of options at each level of the hierarchy. Depth refers to the number of levels in the hierarchy.
If a hierarchy is too narrow and deep, users have to click through a lot of levels to find what they are looking for. If a hierarchy is too broad and shallow, users are presented with too many options on the main menu and the lack of content once they get to the option level.
Consider the following: recognize the danger of overloading users with too many options; group and structure information on the page level; subject the design to user testing. For new web sites, lean towards a broad and shallow hierarchy. This allows the addition of content. Be conservative in adding more depth as you need to prevent uses to make too many clicks.
In a database-oriented model we structure the data using metadata. Metadata links the information architecture to the design of database schema. By tagging information with metadata, we enable searching and browsing.
A hypertext system involves two primary types of components to be linked. These components can from systems that connect text, data, image, video, and audio. This structure provides flexibility but also causes users confusion because hypertextual links are often personal by nature. This structure is good to use to compliment the hierarchical or database models.
It is very important to provide multiple ways to access the same information. Large web sites would require all three types of structure. The top level will be hierarchical, sub-sites are good candidates for database model, and less structured relationships between content can be handled by hypertext.