Unit Dictionary IMC VTC - Virtual Update - September 2nd

1. Our goals are:
1.1. To establish a centralized community unit repository.
1.2. To serve as a resource for learning how to create custom units for EML.

2. Where we are.
2.1. The unit repository will contain all site defined custom units, scoped to their respective site.
2.2. The repository will exist at a central location.

3. What we have been doing.
3.1. We have outlined a draft Best Practices document for creating custom units:
3.2. The list of current (08/2008) custom units defined within Metacat are being formatted for import into the unit dictionary.

4. What we learned from all this.
4.1. Through this effort, we have come across some common areas of improvement for the creation of custom units:
4.1.1. A standardUnit is already available, but it wasn’t used
4.1.2. The unitType is poorly defined (eg, a unit YYYY for the unit for an attribute 'year' when the attribute should have been a datetype instead)
4.1.3. Part of the unit name could have been included as a part of the attribute name
4.1.4. Misspellings that lead to a unit not being found in the list of standardUnits

5. Where are we headed in ABQ?
5.1. Armed with this knowledge we need to open up discussion of the vetting process that has eluded the unit dictionary effort for quite some time.
5.2. At the working group level, we have discussed potential vetting tactics, but this effort needs to be opened up to a broader IM community.
5.3. We will also be discussing access to the unit dictionary.

Other topics visited by the 1500edt group
Problems with EML Standard Unit List: See these links for bugs which have been posted to the EML bug list by LTER members:
To find all submissions that mention "unit", visit: http://bugzilla.ecoinformatics.org/query.cgi
Type "unit" into the text box for the summary, and Choose Product = "EML"
Some of these bugs have been addressed in EML-2.1.0. However, the general feeling (of this group) is that site-level custom units that were submitted to this list probably do not need to be added to EML as part of its standard. For the most part, a "standard" process is being initiated within the LTER for how units should be defined.

Suggestions for vetting process
1. sites should use their own vetting process first. Several will probably want to reconsider what they are calling a customUnit before they submit it to a network.
2. scientist involvement: scientific domains have practices that need to be preserved.
3. make use SI literature and recommendations
4. submissions need to include conversion info
5. may need different levels of vetting for new additions, (more lenient for current custom content?)

Outline also available in the attached powerpoint.

unit_dictionary_imc_vtc.ppt111.5 KB