A separate column should be used for data qualifiers, descriptions, and flags, otherwise there is the potential for problems to develop during analyses. Potential entries in the descriptor column:
- Potential sources of error
- Missing value justification (e.g. sensor off line, human error, data rejected outside of range, data not recorded
- Flags for values outside of expected range, questionable etc.
Mixing numeric and textual data in one column will cause problems with analysis. Sometimes it is necessary to have both, the value and a qualifier.