Specfic Problems: Healthcare
Query can not specify object precisely
Relevant history for low-weight births
(helpful database gets extra stuff)
Objects (N) are not organized according to all
possible access classifications (a) = (Na)
Patients with heart problems, but not HIV
Some objects cover multiple classes
Patient with stroke and HIV
Some objects are misfiled (happens easily to others),
costly/impossible to guarantee avoidance
Psychiatric data in patient with alcoholism