Separate data values from annotations
Best Practice:
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.
Description Rationale:
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.