Move quantity measure to an attribute on unit terms

[paul121]

Originally mentioned by @gbathree here: The fields in a quantity entity This came up again chatting with @AmberS so creating this forum post to tease out this idea a bit further. Generally it seems the quantity measure may create some unnecessary complexity and confusion when combined with the quantity units (we were mostly thinking in the context of inventory and input applications).

Specifically I want to ask: What would it look like to move the quantity measure to instead be an (optional) attribute on each unit term?

@gbathree

I’m finding that measure is not very useful, as I don’t have the need to compare across all volumes or all distances. If I do want to do that, I would use other libraries to merge common units together (in, cm, m, etc.) as needed, and in that case specifying a measure is kind of redundant. Basically, I think units covers the needs intended by measure.

I tend to agree that “units covers the needs intended by measure”. The measure helps provide semantic meaning to “what” a value + unit pair means in the physical world but for humans its easy to derive this from a common unit like “gallons” or “hectares”. Of course since units are a taxonomy and users can enter anything they would like I see how the measure helps to define “what” a more obscure unit might mean like “scoops” (this may be a poor example) where scoop could be predetermined as a volume, weight or count type of measure. However for both of these cases… does’t this mean the measure is just helping to describe the units? And the measure could be associated with each unit? To challenge this theory, are there any units that do have multiple measures? Maybeee ppm in weight and volume?

Separately, I guess the measure is useful right now when creating a quantity that doesn’t necessarily have units. A few examples I can think where this is happening: a qualitative “Plant health (label) rating (measure): 5 (value)” or maybe an observation “Birds seen (label) count (measure): 5 (value)”. What other examples might be here and how distinct are they from quantities with units? It seems that these use-cases benefit from having the measure, but maybe the label + measure could be combined into a unique unit term (with relevant measure) under this proposed structure?

Thought would need to be given for migrating data into this structure… worse case it may not be 100% possible to migrate some quantities without losing their intended “meaning”… but overall would this structure be an improvement? Really looking for input because I’m surely not thinking of all the ways quantities are being used.

[mstenta]

I think you described the use case for measure pretty well…

measure is useful right now when creating a quantity that doesn’t necessarily have units

That said, I agree that when units are chosen the measure could be derived. Maybe we add a measure field to unit terms, and auto-populate the measure field on quantities from the units, when available?

If the presence of measure in the UI is a problem, we could explore options for hiding it too.

Removing it entirely is a lot more problematic, however, because of existing data.

maybe the label + measure could be combined into a unique unit term (with relevant measure) under this proposed structure?

Not sure I understood this. Could you describe an example?