We IT management geeks are pretty familiar with data at different “meta” levels. For example:
- The content of a configuration record: data
- Who can access that content: metadata
- Who can set access permissions on that content: meta-metadata
Trying to keep the layers separated (good luck Savas) is tempting for performance reasons but it’s like trying to shore up an ever-leaking levee in the face of a major storm. Semantic technologies get a lot of power out of the fact that they don’t even try.
I was prompted to write this because I recently learned that it also happens in medicine:
- Hypoparathyroidism: low parathyroid hormone
- Pseudohypoparathyroidism: normal parathyroid hormone levels, but a problem with the parathyroid receptor such that the symptoms are the same as those of hypoparathyroidism
- Pseudopseudohypoparathyroidism: normal parathyroid hormone levels and a normal parathyroid receptor, but presents with the same symptoms as pseudohypoparathyroidism (but without the consequences)
Good luck getting your health insurance to cover a pseudo-disease. Don’t even bother calling them about a pseudo-pseudo-disease.
[UPDATED 2009/5/1: For some reason this entry is attracting a lot of comment spam, so I am disabling comments. Contact me if you’d like to comment.]