Occasionally, an attribute seems to hold multiple values simultaneously.
For example, consider an entity type PERSON, which has Language Spoken as an attribute. A distinguishing characteristic of a PERSON is, that they speak many languages. So, the attribute Language Spoken would seem to require multiple attribute values for each entity of PERSON.
An attribute that seems to require multiple values simultaneously is named a multivalued attribute.
If, in this example, know the level of proficiency for each language, the case for defining extra entity type that is named LANGUAGE SPOKEN becomes strong.
CA Gen does not, and should not, provide for multivalued attributes. Rather, remove an apparently multivalued attribute to its own entity type and relate it to the original entity type using a 1:M relationship as shown in the following illustration.
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