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Re: How to express a photography with FRBR on Flickr

From: Richard Newman <r.newman@reading.ac.uk>
Date: Tue, 6 Sep 2005 15:36:35 -0700
Message-Id: <F7D340C6-39EE-4F25-9672-3F1433B8C4F9@reading.ac.uk>
Cc: semantic-web@w3.org
To: Karl Dubost <karl@w3.org>

   Thanks for this -- you're giving me great motivation!

>> It's questionable at which level the "Photograph" -- "Image file"  
>> distinction is made.
>> I would tend to think that there's a blurring between the Work and  
>> Expression for <http://www.flickr.com/photos/karl/36680383/>, then  
>> each resource which always gets sent as the same sequence of bytes  
>> is a manifestation, of which there are multiple items. (Or  
>> something like that, anyway.)
> Maybe to avoid the problem I could have given an random identification
> <#photo_36680383>
>   a frbr:Work;
>   frbr:Expression <http://www.flickr.com/photos/karl/36680383/> ;
>   dc:title "The gardener slipped through the cracks"@en ;
>   dc:date "2005-07-31";
>   frbr:realization <http://static.flickr.com/ 
> 22/36680383_072987e88e_o_d.jpg> .
> Would it be more satisfactory? As in a work is something where a  
> Web page + one version of the images is one possible expression of it.

I'm not sure. I've sometimes found with the FRBR (and I think Bruce  
would concur here) that it's not always easy to identify the four  
layers for any given situation.

I'm still personally trying to decide, for instance, whether two  
'different' photographs -- taken at two times, by two people, but  
from the same vantage -- count as two Expressions of the same  
photographic Work.

At some point I'll go back over every email I've ever read on the  
topic and try to make my mind up -- then I'll stick it in my essay  
and refer to that in future :D

Certainly I agree that the Expression is the wrong level for things  
with ".jpg" extensions to start appearing. In my mind these are at  
the Manifestation level (with the items being chunks of digital data  
over the wire -- a very literal demonstration of the difference  
between resource and representation!). Or, I could be wrong, and the  
JPEGs are Items.

I think you intend your RDF fragment to be

   a frbr:Work;
   frbr:realization <http://www.flickr.com/photos/karl/36680383/> .

<http://www.flickr.com/photos/karl/36680383/> a frbr:Expression ;
   dc:title "The gardener slipped through the cracks"@en ;
   dc:date "2005-07-31" ;
   frbr:embodiment <http://static.flickr.com/ 
22/36680383_072987e88e_o_d.jpg> .

which looks fine to me (Works are unlikely to have dates, for the  
obvious reason that they're conceptual, so they belong at the  
Expression level).

Thank you for kick-starting my work :D

>> FRBR parts. The set is a work, the page showing the set is lower  
>> down the hierarchy, as is the document itself. The components tie  
>> in at each level -- the conceptual set has the conceptual images  
>> as its parts, while the page set has the manifestations as its parts.
>> This ought to be cast down.

> So how would you express in RDF/n3 a set of Expressions?
> something like this here:
> <#photo_36680383>
>   a frbr:Work;
>   frbr:partOf <#sets_659154> .
> <#sets_659154>
>   a frbr:Work;
>   dc:title "Take a seat, Please…";
>   frbr:Expression <http://www.flickr.com/photos/karl/sets/659154/>;
>   frbr:part <#photo_36680383>;
>   frbr:part <#photo_39993659>;
>   frbr:part <#photo_35644399>;
>   […here other images from the set…]  .

Something like that, yes. It'd be easier to draw a diagram, but:

:setWork a frbr:Work ;
   frbr:realization :setExpression ;
   frbr:part :pw1, :pw2 ... .          # partWork

:setExpression a frbr:Expression ;
   frbr:embodiment :setManifestation ;
   frbr:part :pe1, :pe2 ... .          # partExpression

# Photo hierarchy
:pw1 frbr:realization :pe1 .
:pw2 frbr:realization :pe2 .

So it looks like a ladder.

>> I came up with a thumbnail property. A thumbnail is a derived  
>> 'thing' forked from the main FRBR tree.
> It's also a realization no?
>     frbr:realization <http://static.flickr.com/ 
> 22/36680383_072987e88e_s_d.jpg>;

Yes -- though perhaps an alternative manifestation. I'm brainstorming  
now, but I see it something like this:

Work:          the picture you intended to take. Conceptual, remember.
Expression:    the picture you took, with its title and the time
                you took it.
Manifestation: the picture you took, recorded. The first one of
                these is probably created at the same time as the
                Expression, in the case of photography! Alternative
                Manifestations are created when modifying the
                expression, so a thumbnail or cropped version is an
                alternative Manifestation that accompanies this one.
                Similarly, changing format makes a new Manifestation.
Item:          each copy of a JPEG (bitwise identical) is an exemplar
                of the same Manifestation. So, copying a photo from
                iPhoto to the Web makes a new Item rooted in the same

If you significantly rework a picture, the tree splits higher up,  
making a derived Work. A montage would be a composite work; an  
overlay would be a referential work.

Thoughts? This is a big step for me :D

Received on Tuesday, 6 September 2005 22:36:52 UTC

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