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Exhibit 6-10.
Nonmeaningful indicators.
Person Blue Eye Color Indicator
Person Green Eye Color Indicator
Person Gray Eye Color Indicator
Person Brown Eye Color Indicator
Person Hazel Eye Color Indicator
Exhibit 6-11.
Higher-level indicators.
Person Smoking Indicator
Person Drinking Indicator
Person Exercise Indicator
Person Family History Indicator
Person High Blood Pressure Indicator
Person High Dietary Fat Intake Indicator
To remedy this situation, data elements that comply with the one-concept-
equals-one-data-element rule can be developed for the concepts presented.
A person's job may require the person to determine and analyze trends in
marital relationships from a legal perspective; the data collected using the
previous data element would be inadequate. Such persons would benefit from
modeling their data requirements and constructing more precise data ele-
ments that would conform to the one-concept-equals-one-data-element rule.
Indicators
Homogeneity and mutual exclusivity among valid values help ensure
that the data element addresses only one concept. However, there are
other pitfalls to watch out for in developing valid values. Data elements
with yes or no values are easy to create. They can be easily named and
their valid values are mutually exclusive. But they often mask more mean-
ingful data that may be more useful, and it is easy to end up with several
yes or no data elements when a more comprehensive concept is more
appropriate. The example in Exhibit 10 demonstrates this. The higher-level
concept in the example in Exhibit 11 may be less obvious. These data ele-
ments could be assigned to the entity PERSON. A way to develop one mean-
ingful data element to replace these, however, would be to reassign them as
the valid values for a data element, Person Health Risk Code. This data ele-
ment could be assigned to an entity called PERSON HEALTH RISK, which
would be an associative entity between PERSON and HEALTH RISK. This
associative entity could have data elements to document such additional
concepts as date of onset, duration, and severity.
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