Community:Collections and Metadata/MissingAndInconsistentData

From NSDLWiki

Missing And Inconsistent Data

• Missing data

A Dublin Core record should have at least a title and / or a description. Do we want records without titles, even if cataloger-supplied?

A record should refer to one or more collection(s).

• Inconsistent element use

It is possible that a record will have elements with “no values” such as <dc:date>--</dc:date> or <dc:subject>XXX</dc:subject>. In several cases, the value, or lack thereof, might be considered as information (the fact that the object has no date) but this is of no interest for the purpose information retrieval. For example <dc:date>ND</dc:date> or <dc:date>undated</dc:date> or <dc:creator>unknown</dc:creator>. Therefore, for the prupose of information retrieval, it is recommended that fields with no value be left empty. The data provider should evaluate the effectiveness of “no value” elements for information retrieval in its records before sharing them.

If an element can be repeated in the target metadata format, the values from the original metadata format should not be merged into one element field. It is easier for the service provider to merge them for display than divide them to process the various values within an element field. Moreover, the use of a semi-colon before or after the element value to separate the merged values generates trash values.

When the mapping process adds information, it is important to control the behavious of the system when the original value is null, it may avoid to generate such values as “<dc:creator>et al.</dc:creator> or <dc:creator>and</dc:creator> or <dc:date>1970-01-01</dc:date> (Unix birth date). [Ann: is this what we're tyring to say: "When mapping values from one metadata format to another, it is important to control the behaviors of the system in order to avoid generating values such as '<dc:creator>et al.</dc:creator> or <dc:creator>and</dc:creator> or <dc:date>1970-01-01</dc:date> (Unix birth date)'"?]

• Preserve the context of metadata

Data providers should ensure that their record makes sense outside its context. In a collection of Russian images, each record should contain reference to Russia. Any context useful for information discovery or for information display should be automatically added to each individual record.

A collection level description, either included in the set description or as a record may provide this additional required information.