Chris Rusbridge has a couple of interesting posts (original and followup) about specification and curation. The gist is that he’s reporting some conversations, which I might baldly summarise as saying something like:
- Any application stores data and renders it for consumption (by a human or another layer of software). In the best of possible worlds, a specification for the data structure AND the application functionality should be enough to ensure that a third party could render the data for consumption at the next level without reference to the application code itself. However, certain real world experience suggests that the specifications are not enough, you need the code as well, because real implementors break their specifications.
- There was some discussion about the ability of OOXML and ODT to preserve semantic content preferentially over latex and PDF … (primarily I think because some of the key semantic content would have been in figures which could be parsed for logical content, and both latex and pdf would have turned those figures into images).
- As a consequence, Chris gets to this position:
So ... running code is better than specs as representation information, and Open Source running code is better than proprietary running code. And, even if you migrate on ingest, keep BOTH the rich format and a desiccated format (like PDF/A). It won't cost you much and may win you some silent thanks from your eventual users!
You’ll not be surprised to find I have some opinions on this …
- I think in nearly all the cases where the specification is not enough, it’s because the specification was a) not designed for interoperabilty, and b) was not the definition of the format and functionality. In these cases we find the spec is an a postiori attempt to document the format (almost certianly the problem with the Microsoft and Postscript examples discussed in the links). In particular, in those cases where we’re dealing with preserving information from a format and specification from one vendor, we find both a) and b) violated, nearly all the time. What that says to me is that we should avoid trying to curate information which is in vendor-specific formats in favour of those where there are multiple (preferably open-source) implementations.
- Running code will become non-running code in time, and not much time at that. What I hope Chris means, is keep the source code which ran the application. Even then, every software engineer knows that the code is not documentation, and that with sufficiently complex code, NO ONE will understand it. So, code without specfication is a candidate for obsolescence and eventual residence in the canon of “not translated, not understood, not useful” write only read never (WORN) archives.
What do we do at BADC? (In principle!)
- Preserve input data. Copy on ingest if we have to, but we prefer (for the data itself) to demand that the supplier reformat into a format which does conform to a) designed for interoperability, and b) where there is a specification which preserves enough of the information content. (Duplicates of TB of data are not viable).
- Preserve input documentation. Preserve specifications. Demand PDF (for now). Yes, the images are an issue, but if the images are data, then they ought to be actively preserved as data in their own right.
- Ban MS documentation. History suggests that MS documents become WORN in about 6-8 years. Those who know no history are doomed to repeat it …
So, I would argue that if you are doing curation, you have to address workflow before you get to the point of curation. If you know you want to preserve it, then think about that from the off. If you know you don’t care about the future (shame on you), then yeah, ok, use your cool vendor tool … but don’t give the data to someone to curate, because curation is, in the end, about format conversion. If not now, sometime in the future INEVITABLY. If the documentation doesn’t exist to do it, it’s not curating. Don’t kid yourselves.
All that said, much of the initial conversation was in the context of document curation, not data curation. IMHO the reason for much of what i perceive as confusion in their discussion, is not recognising the distinction! In the final analysis, I think that
- if your object is to curate documents (i.e. what I would call the library functionality), then preserving PDF/A, latex etc, is perfectly fine - after all, with the spec, you’re preserving with the same fidelity that documents have always been preserved.
- if your object is to preserve the data, then it’s a different ballgame, and folk need to confront the fact that curating data requires changes to the original workflow!