ISSUE-135: Collection relations have confusing names

collection-names

Collection relations have confusing names

State:

CLOSED

Product:

prov-dm

Raised by:

Stian Soiland-Reyes

Opened on:

2011-10-29

Description:

http://www.w3.org/TR/prov-dm/#expression-Collection introduces relations for expressing collections;


> Expression: wasAddedTo_Coll(c2,c1) (resp. wasRemovedFrom_Coll(c2,c1)) denotes that collection c2 is an updated version of collection c1, following an insertion (resp. deletion) operation.

> Expression: wasAddedTo_Key(c,k) (resp. wasRemovedFrom_Key(c,k)) denotes that collection c had a new value with key k added to (resp. removed from) it.

> Expression: wasAddedTo_Entity(c,e) denotes that collection c had entity e added to it.


I discussed this with some colleagues who are new to PROV, and they found the names very confusing. For instance wasAddedTo_Coll(c2, c1) sounds like c2 was added to c1.

I understand that this _Coll/Key/Entity dispatching is to keep these as wasDerivedFrom subproperites, and avoid introducing an explicit process execution with three different usage roles.



When encoding this for PROV-O I decided to rename them, but keep them as subproperties of prov:wasDerivedFrom:

http://dvcs.w3.org/hg/prov/raw-file/4b6e3db74001/ontology/Overview.html#collections


As I discussed this, we found that wasAddedTo_Coll(c2,c1) means c2 is like a superset of c1 - but without requiring either to be a set. So we think PROV-DM are describing something like a bag collection of (key,value) pairs, but did not bother checking wikipedia what the equivalent of superset and subset is for bags.

Instead I just opted for "expansion" and "reduction", and use verbs that relate the actual entities:


:col2 a prov:Collection ;
prov:wasExpandedFrom :col1 ;
prov:wasExpandedBy :e2 ;
prov:wasExpandedAt :key2 .

corresponding to:

wasAddedTo_Coll(c2,c1)
wasAddedTo_Key(c2,k1)
wasAddedTo_Entity(c2,e1)



and equivalent for reduction:


:col3 a prov:Collection ;
prov:wasReducedFrom :col2 ;
prov:wasReducedAt :key1 .


I propose to rename the PROV-DM relations for collections to match the PROV-O style above.

Related Actions Items:

No related actions

Related emails:

1. Re: closing old collection issues -> the question of monotonicity of provenance (from Paolo.Missier@ncl.ac.uk on 2012-03-29)
2. Re: closing old collection issues (from soiland-reyes@cs.manchester.ac.uk on 2012-03-29)
3. Re: closing old collection issues (from L.Moreau@ecs.soton.ac.uk on 2012-03-28)
4. Re: closing old collection issues (from satya.sahoo@case.edu on 2012-03-28)
5. Re: closing old collection issues (from L.Moreau@ecs.soton.ac.uk on 2012-03-28)
6. closing old collection issues (from Paolo.Missier@ncl.ac.uk on 2012-03-28)
7. Re: ISSUE-135 ... ISSUE-139 (from soiland-reyes@cs.manchester.ac.uk on 2012-02-22)
8. Re: PROV-ISSUE-135 (collection-names): Collection relations have confusing names [Data Model], ISSUE-137, (from soiland-reyes@cs.manchester.ac.uk on 2012-02-22)
9. ISSUE-135 ... ISSUE-139 (from L.Moreau@ecs.soton.ac.uk on 2012-02-15)
10. Re: PROV-ISSUE-135 (collection-names): Collection relations have confusing names [Data Model] (from Paolo.Missier@ncl.ac.uk on 2011-11-15)
11. PROV-ISSUE-135 (collection-names): Collection relations have confusing names [Data Model] (from sysbot+tracker@w3.org on 2011-10-29)

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