[Data-modeling] relationship type explanations... diagrams?

[jerritt collord]

I'm new here and not sure how normalized I need to think--or what I'm
missing--or if I'm just having a bad day and need to re-read.

Quick explanation of problem: I'm not an engineer but an area I'm interested
in tangentially is materials science. There are tons and tons of possible
properties as one might imagine and I don't think the right solution is to
create a Material type with ~100 properties slots. Or maybe it is?

Obviously the physical properties have to integrate with the fairly complete
system of basic Units in freebase... but e.g. there will be a lot of
mechanical properties all with Units that now carry Units of Pressure
designation.

I know this isn't fruitful, but this is what I tried to do:
-------
type: MaterialPropertyClass
display is Enumeration
example instances: Mechanical property, Magnetic property, Chemical
property, Health property

type: MaterialProperty
display is Standard
properties:
* base SI Unit (single value: reference to appropriate instances of system
Unit type)
* alternative units (multiple values: reference appropriate instances of
system Unit types)
* MaterialPropertyClass (single value: reference to instance of
MaterialPropertyClass, display as disambiguator)
example instances: Density, Magnetic Susceptibility (many of these topics
already exist, unstructured, in freebase probably via wikipedia)

type: MaterialPropertyMeasure
display is Compound (?)
properties:
* Material
* MaterialProperty (single value: references MaterialProperty)
* MaterialPropretyValue (single value: floating point number)
* MaterialPropertyUnits (reference to sytem Unit type)
* MaterialPropretyDesc (single value: text) -- used for non-numeric
Properties, or descriptions of measurements
example instances: Density of Stainless Steel

type: Material
properties:
* etc.
* MaterialsPropertyMeasure (multiple values) ? Here's where I fail to
understand... it seems that what I'd want to do is have all the instances of
MaterialPropertyMeasure that reference this material show up.
----------
Probably too complicated and all but encourages users to stray from standard
units--and unqueryable to boot.

Any guidance for examples of domains/problems that resolve relationships
like these? Basic reading I need to do more of?

Thanks,

Jerritt
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