 database
&gt; &gt; &gt;design (that the data model supports). It might also be a check
&gt; &gt; &gt;you run on the whole database periodically.
&gt; &gt;
&gt; &gt; Eureka!  And that periodic database check would be one way to
&gt; &gt; use a formal
&gt; &gt; ontology, doing data cleaning, checking for data entry typos, against
&gt; &gt; constraints like and individual's birth must come before his
&gt; &gt; or her death.
&gt;
&gt;MW: Quite. But as noted above, this constraint would only pick up
&gt;a small