Re: Temporal validity: alternative for dcterms:valid?

Hi Frans,

"a versioning scheme based on DCMI has a weak spot: the property for denoting temporal validity (dcterms:valid) is impractical to the point of being unusable."

Well, sort of.  If one is trying to rank temporal validity then one is trying to rank the negative pattern of the property.  One has to wake a sleeping naughty boy or girl up to determine  the naughtiness property.  In another familiar case, in a Hospital patients are woken up at all hours to take medications - you can be just as ill at home, with uninterrupted sleep.  This seems to me to be the same logical problem (post hoc ergo propter hoc).

Santa Claus, et al. can do this sort of thing without waking up naughty boys and girls.   An Artificial Intelligence which believes it can do what Santa Claus can do is quite unhinged, I think :)

--Gannon 
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On Thu, 12/24/15, Frans Knibbe <frans.knibbe@geodan.nl> wrote:

 Subject: Temporal validity: alternative for dcterms:valid?
 To: public-lod@w3.org
 Date: Thursday, December 24, 2015, 9:57 AM
 
 Hello again,The DCMI
 Metadata Terms vocabulary seems to have all the basic
 ingredients for building a versioning mechanism in to a
 dataset (which is or should be a very common requirement).
 Objects in a dataset can have life spans (temporal
 validity), be versions (dcterms:hasVersion/dcterms:isVersionOf)
 of another resource and replace each other (dcterms:replaces/dcterms:isReplacedBy).But as Jeni
 Tennison has noted some time ago (see final section
 'Unanswered Questions'), a versioning scheme based
 on DCMI has a weak spot: the property for denoting temporal
 validity (dcterms:valid)
 is impractical to the point of being unusable. Dcterms:valid
 only takes literals (rdfs:Literal) as value, which makes it
 hard to use it for practical expressions of time intervals.
 Time intervals should be compound objects that are based on
 useful datatypes. For instance, xsd:dateTime (for dates) or
 xsd:integer (for years or seconds (e.g. in UNIX time)) could
 be used in SPARQL queries to filter or order temporal data.
 In a versioned dataset queries like 'give me all changes
 between time T1 and time T2' or 'give me the state
 of the dataset at time T3' should be easy to create and
 to resolve. It seems to me that this requires proper and
 well supported data types. A text string notation for time
 intervals is recommended by DCMI: dcmi-period.
 It is easy and versatile enough, but the average triple
 store probably does not recognize this notation as temporal
 or numerical data. So I wonder if there is a good
 alternative for dcterms:valid somewhere that can be used to
 indicate temporal validity.I did find http://www.w3.org/ns/prov#invalidatedAtTime in
 PROV-O, which could be considered applicable, but a matching
 property to indicate the start of the time period of
 validity does not seem to exist in PROV-O. Also, its range
 is xsd:dateTime, which I think is too restrictive because
 the time needs to be known up to the level of seconds.Does this gap still need to be
 plugged? Or is the solution out there?Greetings,Frans

Received on Thursday, 24 December 2015 20:29:39 UTC