Search Illustrated: Tagging Explained
Tagging is the Web 2.0 version of adding metadata to web content, but with an interesting user-generated twist that the earliest forms of metadata lacked. — A W3C recommendation document defined a set of meta tags for web content, including the "keywords" tag.
Context & Ripple Effects
Tagging has been building as a theme across the blogosphere for two years before this explainer: [[a:1175568|posting, subscribing, tagging and search were already being discussed as one workflow back in October 2005]], and MyBlogLog devoted a post to tags just weeks before Search Engine Land ran this piece (All About Tags, May 2007). What the article adds is the historical frame — the W3C once standardized a keywords meta tag so publishers could declare their own metadata, and tagging hands that job to readers.
First-order effects
- Publishers and bloggers who tag their posts gain a second discovery path: tag-based search surfaces such as Quintura's visual tag-cloud search can surface their content even when traditional keyword matching misses it.
Second-order effects
- Search and community tools are pushed to compete on aggregation rather than declaration — whoever collects and ranks the crowd's tags most usefully wins attention that publisher-supplied meta keywords used to arbitrate.
Third-order effects
- If the pattern holds, the authoritative description of web content migrates from standards bodies and site owners to the audience itself, making user-generated signals a core input into how search engines infer what a page is about.
The trend: Metadata authority is shifting from publisher-declared standards like the W3C keywords tag to user-generated tagging, turning audiences into co-indexers of the web.