What is "metacrap"

Metacrap is a derogatory term for metadata, likening it to "crap". The origin of the word is unknown, but it was popularized by Cory Doctorow in a 2001 essay titled "Metacrap: Putting the torch to seven straw-men of the meta-utopia."

In the essay, Doctorow illustrates problems in relying on metadata for knowledge representation in online records or files by drawing humorous parallels to real-world systems, as well as showing examples of metadata collapse in online, web-based systems. The fragility of metadata is an important concern because much planning for improving the web (such as the semantic web) is predicated upon certain flavors of metadata becoming widely adopted and used with care—something which, according to Doctorow's essay, will not and cannot happen.

Doctorow's seven purportedly insurmountable obstacles to reliable metadata are:

1. People lie
2. People are lazy
3. People are stupid
4. Mission Impossible: know thyself
5. Schemas are not neutral
6. Metrics influence results
7. There's more than one way to describe something

Other reasons that result in metadata becoming obsolete (crap) are:

1. Data may become irrelevant in time
2. Data may not be updated with new insights

This means search results can return outdated and incorrect data.