Preview

The preview feature is fairly basic. Most wiki engines have it.

When editing a wiki page, you can click 'Preview' to see how your wiki text will show up after you save. The preview allows you to test out any complicated wiki markup, and make sure the the page will be formatted well. You can carry out further editing before you save your changes.

When you 'save', this will result in an entry on the recent changes display and on this page's version history display. As such, it is generally better to make use of preview, rather than editing and saving and then making more small edits again (Better because we can avoid flooding the recent changes display with lots of niggling little tweaks and formatting corrections)

People who are new to wikis will tend to be unaware of the recent changes display and page version history displays, and their importance in process of wiki collaboration. As such, new users typically can be seen editing saving and editing again several times over to get their formatting right, while more experienced users tend to make fewer messy little edits on recent changes display.

It is important that a wiki engine provides a preview feature to allow users make this progression. The hope is that the whole wiki community will begin collaborating effectively, making heavy use of the 'recent changes' display, and thinking about how their edits will appear on it.

Other related wiki features are Page History, Change Summary, and Minor Changes, all of which come together to provide a simple but powerful platform for collaboration. Wiki software missing any of these features, is probably not worth bothering with.

If wiki software provides an editing process which is truly WYSIWYG, then the preview feature is not necessary, since you can see what it will look like, while you are editing.