True or False: The concept rank is configurable in a keyword expansion.

The statement regarding the concept rank being configurable in a keyword expansion is false. In most systems that incorporate keyword expansion, the concept rank is typically predefined and not adjustable by users during the keyword expansion process. The rank is usually established based on the relevance or importance of concepts in relation to the keywords being used, which helps in organizing the results according to their significance but does not allow for individual configuration. This means that users cannot modify or set the rank for different concepts during the process of keyword expansion.

The other options suggest conditions where the concept rank might be configurable, but in general practice, the ranking system remains fixed, reinforcing that the correct understanding aligns with the notion that it is not adjustable.