DomainLessons - Marine Metadata Wiki

Standard Naming Exercise

Domain Element Lessons

This page contains lessons learned about the 'Domain' element of our variable metadata.

One of the original notions was that a variable name could be made up of a domain, e.g., 'ocean', and what's measured there ('temperature'). So the selection of domain names was biased in the direction of domains that would clarify variable names.

What's a Good Domain?

• Atmosphere felt like a "good" (useful, clear, understandable) domain

• • Corresponding concepts are hydrosphere, lithosphere

• Ocean feels like a good domain

• • but should the domain change as the sensor goes from the ocean to the estuary to the river to the lake?

  • in some cases we are definitely measuring the ocean

  • • that's what people would search on

    • but what to do about the other issues? (see next section)

What Level of Detail?

• Giving everything the same level of domain (e.g., sphere) is too broad for some purposes

• But it's important to recognize domain relationships

• A hierarchy of domains can be effectively exploited

• • see bottom of document for hierarchy so far

• Specify the most precise domain you can

• • we understand that the more precise name implies the higher-level domains

Odd Domains

• What's the domain when the measurement applies to some man-made thing?

• • the thing itself -- an instrument, platform, or sensor

• What's the domain for quality control flags?

• • the data they refer to

• What's the domain for latitude and longitude?

• • some argue for no domain, others for earth or globe or geosphere

  • • (lat/lon exists also on other planets)

    • geo recommended as a generic term that is in common use

  • we settled on geo since it had the least amount of complaining

• What about time and time zones?

• • this is just lat/lon, rotationally speaking

  • decided time is unique unto itself, gets its own domain

  • time zone is really a longitudinal reference, so geo for it (could also be a setting)

Is it a Domain?

• wind: no

• • this is the measurement being taken, more than the component of atmosphere being measured

  • comparative example:

Which Thing is the Domain?

• When measuring distances

• • the material you're measure through? (more clear in English usage) or

  • the material you're measuring to (more uniform/rigorous)?

  • For example, altitude above ocean floor -- is the domain 'ocean', or 'benthos'?

  • we thought that the To usage was clearer

  • • the Domain for altitude above sea level was sealevel (hydrosphere.ocean.sealevel)

    • the Domain for altitude above ocean floor was benthos (lithosphere.benthos)

• When measuring differences across domains (e.g., temperature difference)

• • a joint domain

  • the higher-level domain

  • a new domain

  • just one or the other

  • no domain

  • so far, we have used the higher-level domain (I think)

• When measuring locations

• • the substance you're In (ocean)?, or

  • the platform you're on (platform)?, or

  • the sensor making the measurement (sensor)?

  • we thought it's the substance you're in, except

  • • the derived value MidDepth, the midpoint of a dive, was a deployment domain

Domain List

• hydrosphere

• • ocean

  • • sealevel

    • seasurface (same meaning as sealevel but used in different context)

• atmosphere

• lithosphere

• • benthos

• observatory

• • platform

  • • instrument (definition TBD; typically more complicated than sensor; reporting center?)

    • • sensor (definition TBD; makes single measurement?)

• deployment (some measurements are not about the device itself, but about its usage)

• data