Key differences between Properties and Items:
* Properties have a data type, items don't.
* Items have sitelinks, Properties don't.
* Items have Statements, Properties will support Claims (without
sources).
The software needs these constraints/guarantees to be able to take
shortcuts,
provide specialized UI and API functionality, etc.
Yes, it would be possible to use items as properties instead of having a
separate entity type. But they are structurally and functionally
different, so
it makes sense to have a strict separate. This makes a lot of things
easier, e.g.:
* setting different permissions for properties
* mapping to rdf vocabularies
More fundamentally, they are semantically different: an item describes a
concept
in "the real world", while a property is a structural component used for
such a
description.
Yes, properies are simmilar to data items, and in some cases, there may
be an
item representing the same concept that is represented by a property
entity. I
don't see why that is a problem, while I can see a lot of confusion
arising from
mixing them.
-- daniel
Am 28.05.2014 09:25, schrieb David Cuenca:
Since the very beginning I have kept myself busy
with properties,
thinking about
which ones fit, which ones are missing to better describe reality, how
integrate
into the ones that we have. The thing is that the more I work with
them, the
less difference I see with normal items.... and if soon there will be
statements
allowed in property pages, the difference will blur even more.
I can understand that from the software development point of view it
might make
sense to have a clear difference. Or for the community to get a deeper
understanding of the underlying concepts represented by words.
But semantically I see no difference between:
cement (Q45190) <emissivity (P1295)> 0.54
and
cement (Q45190) <emissivity (Q899670)> 0.54
Am I missing something here? Are properties really needed or are we
adding
unnecessary artificial constraints?
Cheers,
Micru
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--
Daniel Kinzler
Senior Software Developer
Wikimedia Deutschland
Gesellschaft zur Förderung Freien Wissens e.V.
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