On 07/01/2018 21:34, Martin Doerr wrote:

Dear All,

Here my guidelines:

Guidelines for using P82a, P82b, P81a, P82b

... should be '81a, 81b, 82a, 82b'

Jan 7, 2018

The range of properties "P81_ongoing_throughout" and "P82_at_some_time_within" is  defined in the CRM as E61 Time Primitive, i.e., (closed, contiguous) intervals on the natural time dimension in which we live.

Since the E61 Time Primitive of the CRM cannot directly be implemented in RDF databases, we define in

replace 'implemented in RDF databases' by 'expressed in RDF'

the official RDF implementation of the CIDOC CRM four properties replacing P81 and P82 adequately using xsd:dateTime.

Property P81 describes the maximum known temporal extent of an E52 Time-Span, i.e. the extent it is ongoing throughout.  It is replaced in this RDF version by the property "P81a_end_of_the_begin"  and "P81b_begin_of_the_end", to be used together.

 "P81a_end_of_the_begin" should be instantiated as the earliest point in time the user is sure that the respective temporal phenomenon is indeed ongoing. We call it “end_of_the_begin”, because it also constitutes an upper limit to the end of the indeterminacy or fuzziness of the begin of the described temporal phenomenon.

replace 'begin' by 'beginning' [of the described ...]

"P81b_begin_of_the_end" should be instantiated as the latest point in time the user is sure that the respective temporal phenomenon is indeed ongoing. We call it “begin_of_the_end”, because it also constitutes a lower limit to the begin of the indeterminacy or fuzziness of the end of the described temporal phenomenon.

It is correct to assign the same value to P81a_end_of_the_begin and P81b_begin_of_the_end, if no other positive knowledge exists. It is also correct not to instantiate P81 for a time span, if no respective evidence is known.

replace 'if ... known' by 'if there is no evidence that the event was definitely occurring at a particular time'?

If a respective reasoning is installed, and no evidence exists that the phenomenon was definitely ongoing at any point in time, one may use a value for P81a_end_of_the_begin greater than for P81b_begin_of_the_end, indicating that the indeterminacy of knowledge (not of being) of the begin overlaps with the indeterminacy of knowledge (not of being) for the end [see Christian-Emil Ore XXX].

Is it helpful to say this? Why not just leave P81 out in this situation?

If a value for P81a_end_of_the_begin is given with a precision less than that of xsd:dateTime, such as in days or years, the implementation should “round it up” to the last instant (second) of this time expression, e.g. 1971 = Dec 31 1971 23:59:59. Respectively, if a value for P81b_begin_of_the_end is given with a precision less than that of xsd:dateTime, such as in days or years, the implementation should “round it down” to the last instant (second) of this time expression, e.g. 1971 = Jan 1 1971 0:00:00. If

replace 'last' by 'first'?

values are needed that are not within the range or precision of xsd:dateTime, e.g., for paleontology, this property should be extended with another, suitable data type.

Property P82 describes the narrowest known outer bounds of the temporal extent of an E52 Time-Span, i.e. the extent it is ongoing “at some time within” this interval.  It is replaced in the official RDF version by

delete 'the extent'

the properties "P82a_begin_of_the_begin" and "P82b_end_of_the_end", to be used together.

" P82a_begin_of_the_begin " should be instantiated as the latest point in time the user is sure that the respective temporal phenomenon is indeed not yet ongoing. We call it “begin_of_the_begin”, because it also constitutes a lower limit to the begin of the indeterminacy or fuzziness of the begin of the described temporal phenomenon.

replace 'ongoing' by 'happening'?; replace 'begin' by 'beginning' [of the described ...]

" P82b_end_of_the_end " should be instantiated as the earliest point in time the user is sure that the respective temporal phenomenon is indeed no more ongoing. We call it “end_of_the_end”, because it

replace 'no more' by 'no longer'

also constitutes an upper limit to the end of the indeterminacy or fuzziness of the end of the described temporal phenomenon.

It is not correct to assign the same value to P82a_begin_of_the_begin and P82b_end_of_the_end. If a value for P82a_begin_of_the_begin is given with a precision less than that of xsd:dateTime, such as in days or years, the implementation should “round it down” to the last instant (second) of this time

replace 'last' by 'first'?

expression, e.g. 1971 = Jan 1 1971 0:00:00. Respectively, if a value for P82b_end_of_the_end is given with a precision less than that of xsd:dateTime, such as in days or years, the implementation should “round it up” to the last instant (second) of this time expression, e.g. 1971 = Dec 31 1971 23:59:59.

It must always hold that the value for P82a_begin_of_the_begin is less than P82b_end_of_the_end, P81a_end_of_the_begin and P81b_begin_of_the_end.

It must always hold that the value for P82b_end_of_the_end is greater than P82b_end_of_the_end,

should be 'greater than P81a_begin_of_the_begin,'

P81a_end_of_the_begin and P81b_begin_of_the_end.

P82a_begin_of_the_begin and P82b_end_of_the_end should always be assigned a value to for any past

delete 'to'

phenomenon, albeit unrealistically far away from reality. It is an error to associate any quality of positive

replace 'albeit ... reality' by 'however approximate'

knowledge with these values. The scholarly practice not to give any outer bounds for an event, because it is, for instance, not known down to a precision of three years, is not helpful for automated reasoning. In that case, the machine may regard that the event has possibly happened at the time of the dinosaurs.

replace 'regard ... possibly' by 'conclude that the event could have'

Hope this helps!

Richard

Please improve.

Cheers,

Martin

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