Data Quality

Quality data...

... is structured similarly to dataset X using uniform vocabulary.
... is structured similarly to dataset X.
... I [dis]agree with.
... I understand.
... is complete.
... explicitly connects to the data currently portrayed in visual artifact X. (e.g. A book's two pages, currently visible)
... explicitly connects to the data portrayed in visual artifact X. (e.g. An entire book, yet to be opened)
... explicitly connects to dataset X.
... I find interesting.
... explicitly connects to other datasets. (i.e. TBL-5)
... is in RDF that I can retrieve as a dump.
... is in RDF that I can retrieve via SPARQL query.
... is in RDF that I can retrieve with dereferencable URIs.
... is in RDF that I can retrieve.
... is in RDF. (i.e. TBL-4)
... I can retrieve and is machine processable using my own (or open) tools. (i.e. TBL-3)
... I can retrieve and is machine processable. (i.e. TBL-2)
... I may and can retrieve. (i.e. TBL-1)
... I may retrieve. (i.e. open)

situate:

Number of triples for each dataset
Number of datasets
Number of interlinks [from each dataset [to each other dataset]]
Accessible via data dump, accessible via SPARQL query, accessible via crawling
For each property in a dataset, the number of extra-namespace URI values that are dereferencable
Density: Number of extra-namespace URI values in a dataset / The size of the dataset.
Density: Number of extra-namespace URI values in a dataset / Number of instances of a given class in the dataset.

Tummarello 2007

Ding 2005

Wang 2006

Lengths of terms (URI, bnode, and literal)
Term prefix and suffix
Frequency occurrence of a term in position S, P, or O.
- covers "number of triples per predicate" (270-1,000s)
- 2-20 triples per subject.
"Simple" and "Double" Projections
Star signatures (set of predicates in/out) of every graph node -- causes "star classes". Number and sizes of star classes can reflect uniformity in a graph.
Path patterns from a source and target node.

Number of crawl seed URIs (42,500 from a 2009 crawl)
Number of [unique] {quads,triples} crawled from number of documents ([1.106 BQ] 1.118 BQ, [947 MT])
Time period[s] crawled (May 2010 and 9 monthly March-November 2010)
Number of data providers, according to Pay-Level-Domains (778)

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