Dear Robert, All,
Your proposal well taken, but the recent change in the scope note was
exactly that "The properties of the class E54 Dimension allow for
expressing the numerical approximation of the values of instances of E54
Dimension. ".
The point is, that true numerical values of Dimensions do not exist for
continuous value spaces. Therefore, any measurement and opinion about
the values are approximations.So, there is no need for another property.
Measurements have typically known tolerances, which may be statistical,
as mean deviations, or absolute.
The property P189 was introduced because of the huge number of
geo-referenced resource with no indication how distant or different the
approximating area is from the real place. For any approximation with
known inclusion or overlap properties to the real place, P189 should NOT
be used. A "real place" can be confirmed by multiple observations for
things that do not move or have not moved.
This scenario does not exist in the same way for dimensions *in general.*
*
*
I recommend to adjust scope notes and guidelines adequately. If a
dimension is given as 10cm, it is per definitionem an approximation,
because no natural thing has dimension
10,00000000000000000000000000000000000000000000000000000000000000000000000
cm.
A fine example of measurement tolerances is the recent problem of
determining the proton radius:
https://en.wikipedia.org/wiki/Proton_radius_puzzle
See also:
http://pdg.lbl.gov/2012/reviews/rpp2012-rev-history-plots.pdf
https://www.quantamagazine.org/proton-radius-puzzle-deepens-with-new-measurement-20160811/
I think it is a question of guide lines how to interpret the absence of
P10a,b.
Opinions?
Best,
Martin
On 10/15/2019 7:13 PM, Robert Sanderson wrote:
Dear all,
In recent history, we have added P189 approximates for the practically
ubiquitous scenario where we have recorded the approximate
“declarative” place of an event, but not the exact “phenomenal” place.
P189 allows us to say that the event took place at the phenomenal
place, which is then approximated by the declarative place.
Thus:
Birth_of_Rob a E67_Birth ;
p7_took_place_at [
a E53_Place ;
rdfs:label “The exact place Rob was born” ;
p189i_approximated_by [
a E53_Place ;
rdfs:label “New Zealand” ;
// …
]
]
This gives us two significant advantages:
1. We can have multiple declarative places associated with the single
phenomenal place. This allows us to be clear that the event took
place in one location, but we have multiple ways to describe that
location in our information system.
2. If we can be precise (enough) about the phenomenal place (e.g. we
have the GPS coordinates from the digital camera that took the
photograph), then we do not have a different model … we can simply
ascribe those coordinate values to the phenomenal place.
While the E53 Place scope notes do not talk about approximation, there
is another class that does … the very next one, E54 Dimension.
An instance of E54 Dimension represents the true quantity, independent
from its numerical
approximation, e.g. in inches or in cm.
However, there isn’t a property that allows us to use this same
approximation pattern for Dimensions.
The same advantages would apply:
1. We can have multiple declarative dimensions (10 inches, 25
centimeters) that approximate the true dimension, rather than
implying there are two different dimensions.
2. If we do not have this case, because the dimension is measured
very accurately and has only a single numerical representation,
then we can simply use a single Dimension.
This is also useful for conservation when the same dimension is
measured to different degrees of accuracy with different instruments
or techniques … there is only a single height (for example) but it is
measured with a laser, or by estimation.
Thus I would like to propose the addition of a new property,
Pxxx_approximates_dimension, that mirrors P189_approximates, that
would be used to associate true dimensions with their approximations.
It would be used in exactly the same way as P189:
painting a Human-Made_Object ;
has_dimension [
a Dimension ;
p2_has_type <aat:height> ;
pxxxi_dimension_approximated_by [
a Dimension ;
p90_has_value 10 ;
p91_has_unit <aat:inches>
]
]
Thank you for your consideration of this issue! I’m happy to write up
a draft scope note for discussion if the general issue is considered
to be worthy of inclusion.
Rob
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------------------------------------
Dr. Martin Doerr
Honorary Head of the
Center for Cultural Informatics
Information Systems Laboratory
Institute of Computer Science
Foundation for Research and Technology - Hellas (FORTH)
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GR70013 Heraklion,Crete,Greece
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