Allow DV_QUANTITY, qualified real property values with no units.

Could this be a case similar to DV_SCALE? There are scores such as PASI score which require decimal numbers with no predermined values, and no unit. Using DV_QUANTITY with property “Qualified real” and unit “1” is indeed cumbersome. I’d support DV_NUMERIC or similar.

I like Ian’s suggestion to make the units optional.

and by definition, DV_SCALE does involved pre-defined and fixed numerics.

There are definitely places where a simple real number is required, and that is why ' Qualified real' i.e “1” (which comes from UCUM) exists.

One simple option would be to drop the units mandation, such that an empty units is assumed to be equivalent to “1” i.e a simple unitless real number. Given that we are no longer tied to UCUM that might make sense.

We have real needs to score a number that is not a ratio, without a unit. This is mainly for scores - and we have quite a lot of those. Some of these could be solved with a DV_SCALE, because they are a number with a range with a clear distinct meaning per range. Others are just a number, for a human to interpret the meaning of.

The problem of DV_SCALE for these kinds of things is that it does not have precision, so we cannot as easily say ‘this is a scale with a precision of 2, and every real number between 1 and 3 means …’., so DV_SCALE would currently mainly work well for predefined values, as ‘exactly 1.5 means ..’ and ‘exactly 2.3 means …'.

We currently use DV_QUANTITY with units “1” - and it works. Our tooling takes away the cumbersomeness by offering a dedicated option for a quantity without a unit, which then automatically becomes “1”. In these cases we use a separate DV_CODED_TEXT in case there is also a symbol attached.

With a very limited set of scores there’s also the possibility that there are several ways/variants to interpret a given score, so a DV_SCALE may not be of use there because of the fixed relation between a range and the symbol - but I guess that could be solved with specialisations.