- From: Kashyap, Vipul <VKASHYAP1@PARTNERS.ORG>
- Date: Fri, 12 Jan 2007 10:21:17 -0500
- To: "Ora Lassila" <ora.lassila@nokia.com>, "w3c semweb hcls" <public-semweb-lifesci@w3.org>
- Cc: "Trish Whetzel" <whetzel@pcbi.upenn.edu>, "kc28" <kei.cheung@yale.edu>, "Alan Ruttenberg" <alanruttenberg@gmail.com>, "Nigam Haresh Shah" <nigam@stanford.edu>
> my experience is that issues of versioning are quite different from the > issues of temporal modeling. Often in the former case, we don't have to > concern ourselves with what changes have taken place, whereas in the > latter > case, we often need to focus on the changes themselves (i.e., questions of > what changes, how, and *when* are critical). [VK] That is a good way to distinguish the issues. Unfortunately, the few use cases that were provided to me suggested issues of versioning were confounded with issues of temporal data modeling. The latter notion of versioning is from the content management perspective, where the notion of what.why,who changed it is important, i.e., provenance. This underlines the need for a clear definition of versioning and provenance in the life sciences context. > This is an old and difficult problem with systems employing complex > representations of the world. It is often not sufficient to operate within > a > mere snapshot of the world. One has to ask whether time (or the changes > over > time) matter, or whether at any moment it is sufficient to consider a > snapshot. [VK] The key is how you support this functional requirement. Either you could create an appropriate temporal model that provides the framework acquisition and querying of this data; or you could fall back on versioning functionality to get this information. IMHO, there is more value in taking the former approach as it can be fed into versioning systems that compute the changes or "diffs" > One might draw analogies to "compile-time vs. run-time" considerations > often > occurring in computer science... in fact, the question of "class changes > vs. > instance changes" is exactly that. [VK] Agree. However whether an instance is actually changing or whether a particular property of the individual is naturally modeled as a dynamic time varying data type need to be identified. > BTW, there is a paper that points out that temporal modeling/reasoning is > re-invented/re-implemented over and over because of the lack of "built-in" > support for it in KR systems: > > Thomas L. Dean and Drew McDermott. Temporal Data Base Management. > Artificial > Intelligence, 32(1):155, 1987. [VK] Thanks for the above info. ---Vipul THE INFORMATION TRANSMITTED IN THIS ELECTRONIC COMMUNICATION IS INTENDED ONLY FOR THE PERSON OR ENTITY TO WHOM IT IS ADDRESSED AND MAY CONTAIN CONFIDENTIAL AND/OR PRIVILEGED MATERIAL. ANY REVIEW, RETRANSMISSION, DISSEMINATION OR OTHER USE OF OR TAKING OF ANY ACTION IN RELIANCE UPON, THIS INFORMATION BY PERSONS OR ENTITIES OTHER THAN THE INTENDED RECIPIENT IS PROHIBITED. IF YOU RECEIVED THIS INFORMATION IN ERROR, PLEASE CONTACT THE SENDER AND THE PRIVACY OFFICER, AND PROPERLY DISPOSE OF THIS INFORMATION.
Received on Friday, 12 January 2007 15:25:08 UTC