Are different versions of the same event unique?

[Roy Williams]

On 3/29/12 2:01 PM, Alasdair Allan wrote:
>  The IVORN is the event, not
> the packet, identifier.

Thank you for this Alasdair, absolutely agree. Keep the Representation 
separate from the Data. I would also like to add Meaning to the stack:

(1) Meaning: eg Betelgeuse goes supernova
(2) Data: a packet with VOEvent semantics,
	that is used to carry information about (1)
(3) Representation: of (2) as a byte sequence in XML or other

Thus the signature goes with (3) and the IVORN with (2).

Of course (1) is really a hypothesis -- that the various observations 
support a particular physical explanation.

Thus in Skyalert we have used the Citation semantics of VOEvent to build 
a "portfolio" of observations: data packets as in (2). The Meaning is 
then carried by the portfolio.

Roy


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Caltech LIGO
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