[provenance-challenge] Re: clarifying queries

[Paolo Missier]

Paul,
> I think this is a problem that we should definitely take up, are there 
> ways to commonly refer to values...? I mean right now it's hard to 
> determine what content is available in the value field of each 
> artifact, hence, your suggestion of using annotations. Does something 
> like this need to be part of OPM.
I think the issue of representing (references to) values has come up 
quite clearly throughout the challenge, with proposals such as using the 
value field to keep refs to values (URIs), and then annotating the OPM 
graph with references to services that are able to de-reference those URIs.

At the same time, I reckon adding annotations to causal graphs will 
become inevitable at some point -- and these have the advantage over 
actual values of being generally well-bounded in size, so I suggest we 
address this during the meeting so it is done in a principled way.

Regards, -Paolo