tag:blogger.com,1999:blog-4503292949532760618.post6731375651272996871..comments2024-03-28T13:39:27.601-07:00Comments on DSHR's Blog: PREMIS & LOCKSSDavid.http://www.blogger.com/profile/14498131502038331594noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-4503292949532760618.post-58582183814341062862014-03-31T05:47:29.706-07:002014-03-31T05:47:29.706-07:00And furthermore:
‘it would be possible to impleme...And furthermore:<br /><br /><b>‘it would be possible to implement it because LOCKSS supports similar semantic units to those that PREMIS describes’: :</b> It is important to note that PREMIS is completely implementation independent. It is only a data dictionary – that is a way of organising your domain model with applicable semantic units that describe the entities in the model. It helps you think about your domain and its requirements. It does not at all specify how you implement it and almost everything is optional rather than mandatory – so that you can chose only what is needed by you.<br />I have identified what I have called 5 degrees of freedom, in the past. We have used them as the basis for the conformance statement in PREMIS.<br />1. A repository is free to implement its semantic units using names different from those defined in the PREMIS data dictionary.<br />2. A repository is free to implement its semantic units at higher or lower granularity than defined in the PREMIS data dictionary.<br />3. An implementation can extend extensible PREMIS semantic units with other semantic units (this is isomorphic to using greater granularity)<br />4. An implementation does not have to record mandatory metadata explicitly if it can generate it for exchange<br />5. Controlled vocabulary is recommended but not compulsory.<br /><br />The important conclusion is that it does not matter in what form you store your preservation metadata as long as you can produce an export format that can be mapped to the data dictionary.<br /><br />From what you say it sounds as if LOCKSS is actually PREMIS conformant.<br />Anonymoushttps://www.blogger.com/profile/05088176522353532300noreply@blogger.comtag:blogger.com,1999:blog-4503292949532760618.post-49297215538793675832014-03-31T05:46:33.113-07:002014-03-31T05:46:33.113-07:00David, we have already exchanged thoughts, but sin...David, we have already exchanged thoughts, but since I am concerned about this blog potentially discouraging people from using the de-facto PREMIS standard based on misunderstandings, I wanted to clarify a few things here. <br /><br /><br /> <b>‘ As with OAIS, there are significant conceptual mismatches’:</b> You will be interested to know that in the coming version of PREMISv3.0 we make an explicit effort to break with the OAIS tradition. We have analysed where the focus on OAIS has let to modelling inconsistencies and unnatural breaks in the life-cycle management and are eliminating those.<br /><br /> <b>‘‘the concept of "digital object" is hard to apply to preserving an artifact’:</b> I fully agree with this and had to make all sorts of adjustments and exceptions in data modelling to cope with this in the past. <br />In order to create metadata you have to have an underlying domain model of objects, agents, events, rights, environments, etc. so that you can attach metadata to the instances of these entities. There is no way around that – whether this is in XML, spreadsheets, relational databases etc.<br />But more importantly, when you process the digital assets the software that processes them has to have the same underlying data models. You cannot really avoid having to create it. <br />But - you can certainly avoid excessively detailed data models in both cases – you should! But PREMIS certainly does not encourage users to get overly complex.<br /><br /> <b>‘ As regards format metadata such as is generated by JHOVE, we are skeptical of its utility’::</b> Again, any metadata that you capture, whether in PREMIS or any other metadata framework needs to be based solely on your business requirements. The question is, what functions do I need to perform and what do I need to know in order to do that? The latter part determines which metadata you choose to collect. JHOVE offers you lots of metadata, but the institution who manages the digital assets needs to determine what of it it needs to extract and store – rather than extract on demand or not use at all.<br />So this does not really have much to do with PREMIS, other than that PREMIS offers you the right sort of semantic units where you can store this information if you decide to do so.<br /><br /><b>‘As regards bibliographic metadata’:</b> PREMIS does not actually have any semantic units for bibliographic metadata. It is assumed that there are other frameworks in which one can deal with those. PREMIS has so called intellectual entities, which are at the moment simply pointers to bibliographic metadata that might be held elsewhere. We will make some changes to ‘intellectual entities’ in version 3 so that one can better link to rights or events that may be described in PREMIS, but the underlying principle remains the same: bibliographic metadata is out of scope.<br />Anonymoushttps://www.blogger.com/profile/05088176522353532300noreply@blogger.com