Information Modeling and Relational Databases, 2nd Edition

1.1. Information Modeling

It’s an unfortunate fact of life that names and numbers can sometimes be misinterpreted. This can prove costly, as experienced by senior citizens who had their social security benefits cut off when government agencies incorrectly pronounced them dead because of misreading “DOD” on hospital forms as “date of death” rather than the intended “date of discharge”.

A more costly incident occurred in 1999 when NASA’s $125 million Mars Climate Orbiter burnt up in the Martian atmosphere. Apparently, errors in its course settings arose from a failure to make a simple unit conversion. One team worked in U.S. customary units and sent its data to a second team working in metric, but no conversion was made. If a man weighs 180, does ...