[Obi-protocol-application-branch] inputs and outputs

[Matthew P. <mat...@nc...>]

Hi,

I'm still unsure what the difference between the general association 
has_participant and the more specific has_input and has_output associations 
is. Do we intend to have an OWL sub-property relationship between 
has_participant and these two, or did we intend to stick with the one 
property but have specialised roles?

I ask for two reasons. Firstly, input/output has been spoken of in terms of 
being a role played by something. Hence, it would make sense to subclass Role 
with Input/Output.  For example, Role > Output > Product. It seems to me that 
certain roles only make sense in relation to things that are inputs or 
outputs.

Seccondly, OWL is rubbish at reasoning about property hierachies. So, if we 
went down the specialised-property rout for identifying inputs and outputs, 
we will have very little chance of using a reasoner to identify what is going 
on without fully specifying it all in advance - that is, the reasoner will 
only be able to tell us more general things than we have manually asserted. 
In contrast, OWL is very good at reasoning about classes, so if the 
input/output information is encoded there, we can reasonably expect to get 
out more explicit knowledge than we explicitly assert.

I'm still not sure what is meant by input and output in process, so perhaps 
this is all off on a bit of a tangent. To me, an input is something that 
participates in and had existence before the process. An output is something 
that participates in and has existance after the process. Things consumed by 
a process are inputs and not outputs. Things produced by a process are 
outputs and not inputs. Modifiers are both inputs and outputs. There are even 
things that exist during the process but not before or after it - 
intermediates? Transients? Any specification of what things are 'interesting' 
to us, or why we would want to keep a particular product IMHO lives naturally 
in the PLAN, not the process. This is all trivial to codify as an OWL 
hierachy, and should be relatively clear to use.

However, it is possible that OBI or BFO mean something different by input and 
output, in which case I'd appreciate being de-confused.

Matthew