CMR Metadata Case Study (2017)

The focus of this Case Study is to identify and compare the usage of metadata elements and attributes in CMR metadata collections as well to identify and compare the completeness of UMM-Profile concepts in CMR metadata collections. The field usage studies include a comparison of NASA metadata with IDN and SciOps metadata as well as an evaluation of Commonly Used Documentation Objects (CUDOs).This work updates our analysis of CMR metadata in several important ways:

1)     We retrieved new metadata records for all collections in the CMR during March 2017. This increased the size of our sample from ~4000 records from the NASA DAACs to over 32,000 records from the DAACs, SciOps, and the International Directory Network (IDN).

2)     We added a new metric to our calculations that reports the % of records in a metadata group (e.g. DAAC) that include a concept or item. This provides important information for the collection managers as well as providing information on the usage of various metadata elements. For example, we can distinguish items that occur once in every record from those that occur multiple times in some records.

3)     We developed new visualizations for comparing metadata collections and used these visualizations to compare:

1. DAAC records in 2016 to DAAC records in 2017
2. DAAC records to SciOps records
3. DAAC records to IDN records

UMM-Collection Completeness

We examined completeness of the NASA and IDN metadata groups with respect to the UMM-Collection recommendation. Nine of the fifteen required elements are complete in all these metadata collections. The results are presented in Summary Tables that include links to information describing the concepts in the ISO Explorer as well as links to table that show the records that are missing various elements.

Commonly Used Documentation Objects

All scientific documentation includes contact information for people and organizations, identifiers, references to external resources (online and offline), spatial and temporal extents, keywords, and other items that occur multiple times. ISO metadata includes standard representations for these objects (and others) and it is helpful to use these standard representations as templates throughout a metadata collection.

We examined usage of these Commonly Used Documentation Objects (CUDOs) across NASA and IDN Collections and identified a number of differences across collections. The email element of the contact information is important across all contact information but it is absent from many collections and contact sections.

NASA Metadata Evolution

This report updates the metadata evaluation that we did during 2016 and provides an opportunity to identify how the CMR metadata have evolved over the year. The total number of records increased by over 50% during this time. We introduced a new visualization to summarize this comparison. This Table summarizes the results and provides links to Tables that show the elements that changed:

The largest change in this Table is forty-eight elements that were introduced to the metadata during 2017. The deletion of twenty-one elements that existed in some collections in 2016 and in none during 2017 was primarily due to an improvement in the translation from the CMR into ISO. 

• Commonly Used Documentation Objects (CUDOs)
• Comparing element usage in NASA 2016 vs NASA 2017 metadata collections in the CMR
• Comparing element usage in NASA vs Other metadata collections in the CMR
• Comparing element usage in NASA vs SciOps metadata collections in the CMR
• UMM-Collection Metadata Completeness in the CMR
• UMM-Collection Metadata Usage