Chapter 2. Defining the Wiki

Despite its name, and to borrow the title of a recent blog posting that made me smile, a wiki is not a character in Star Wars.

Webster’s dictionary defines a wiki as “a website that allows visitors to make changes, contributions or corrections.” Wikipedia defines its underlying technology as “a website that uses wiki software, allowing the easy creation and editing of any number of interlinked webpages, using a simplified mark up language or WYSIWYG (What You See Is What You Get) text editor within the browser.” Just to further muddy the waters, the inventor of the wiki, Ward Cunningham, describes it as “the simplest online database that could work.”

So which is it?

The truth is, a wiki is all of those things and more.

Yet, at its core a wiki is simply a website that can be edited directly in your browser without the need for any additional software.

In his book, The Wiki Way: Quick Collaboration on the Web[Cunningham01], wiki creator Ward Cunningham expands on his “database” statement and gives the following more detailed view of the concept of a wiki:

While most people associate wikis with collecting and publishing existing information, a wiki can also be used for authoring and delivering new content. From a content development and publishing perspective a wiki provides the perfect location for a group of authors and subject matter experts to collaborate. This powerful concept opens up the traditional lone author process into one where the knowledge and expertise of external contributors and knowledge holders can be quickly and easily leveraged.

Wikis are much more than a simple collection of separate webpages devoted to individual subjects. Through the addition of hyperlinks, which link pages and articles to each other, the wiki comes closer to Cunningham’s vision of a database, but a database that can be easily browsed, navigated, and searched.

The content of a wiki can have structure and formatting applied through the use of a simple markup language, or more commonly, through the use of a rich text editor (another name for a WYSIWYG editor). For those who prefer to use a markup language, most wiki markup is simpler than the HTML (HyperText Markup Language) used to build traditional static websites. Wiki markup languages were developed to overcome the inherent complexity of HTML, which because it mixes content and formatting markup, can be difficult to edit directly.

While there is currently no international standard for wiki markup, and different wiki developers tend to use their own variants, the basics can usually be mastered in less than an hour. However, at the time of writing most wiki software ships with a rich text editor, and it is possible to use a wiki without having to ever see an instance of the underlying markup language.

In addition to allowing users to edit content, most wikis also allow users to provide a short summary of why they made changes. This information isn’t displayed on the wiki page itself, but is kept as part of the page’s history and can easily be retrieved. This way it is possible to see who made changes and why. Most wikis also keep a copy of each version of a page and include a “roll back” feature that lets you restore an earlier version of the page. Some wikis also include a “diff” functionality that lets you compare two versions of a page side-by-side and see exactly where changes have been made.

This makes many wikis usable as simple content management / revision control systems, which previously would only have been possible by using separate high-cost third-party software applications.

Navigation between the pages of a wiki is achieved through the use of hypertext links. This technique generally leads to a flat navigation structure, rather than a more formal, hierarchical structure. Links are created in wikis using a simple syntax, and it is a common practice in wikis to create a link to a page that does not yet exist in the hope that the existence of the link will encourage another participant to supply the required content for the missing page. Many wikis also include a backlink feature so you can see which pages link to the page you are currently viewing or editing.

Despite the inherently flat structure of wikis, it is still possible to create traditional, hierarchical navigation structures such as a table of contents.

The flat, some would say anarchic, format of wikis can present a management and maintenance challenge. To help with this most wikis provide ways of categorizing and tagging pages. These tags can then be used to generate sidebar lists of categories, or even a “tag cloud,” a structure that displays tags in larger or smaller type depending on their relative popularity.

Studies have shown that among the “Internet generation” – those born since the beginning of the Internet in the mid-1990s – the first reaction of over 50% of users when they need to find information is to use a search tool rather than navigate through a series of steps. Wikis support this growing behavior pattern; most offer at least a title-based search, and many include full-text search capability. The performance and scalability of these searches can vary depending on whether the wiki engine uses an underlying database.

Several wikis also support the integration of third-party search engines such as Google. Understanding your search needs is critical to the successful implementation of a wiki. You may need to develop a metadata strategy to tag pages and wiki sections to assist built-in search engines, or you may need to integrate a third-party tool.