Alistair,

I did start an analysis of RDA and MARC, but didn't get very far. I'll 
take that up again. What I was mainly finding is that there are a lot of 
RDA elements that are listed for more than one MARC element, e.g.

$a Personal name* = 9.2.2 Preferred Name for the Person*
$b Numeration = *9.2.2 Preferred Name for the Person

There are ones that go the other way, as well, where RDA is more 
specific than MARC. It made me wonder how it is that we use the specific 
MARC elements: are they needed for display? do they help input? are they 
arbitrary?

I haven't looked at MODS, however, and there isn't a mapping provided 
between MODS and RDA. I'll think about that, however.

kc

*Alistair Miles wrote:
> Hi all,
>
> This is just an update to say that I've converted the LOC/scriblio
> data to marc xml and from there to mods xml. My next step is to do
> some analysis of the loc data in mods xml to get an overview of the
> elements used, then to try to design at least a partial mapping from
> mods xml to RDF using the RDA and FRBR schemas.
>
> FYI the marc xml and mods xml versions of the LOC/scriblio data can be
> downloaded from the links below...
>
> http://dcmi-rda.s3.amazonaws.com/locdata/part01-marcxml.tar.gz
> http://dcmi-rda.s3.amazonaws.com/locdata/part01-modsxml.tar.gz
> http://dcmi-rda.s3.amazonaws.com/locdata/part02-marcxml.tar.gz
> http://dcmi-rda.s3.amazonaws.com/locdata/part02-modsxml.tar.gz
> [...]
> http://dcmi-rda.s3.amazonaws.com/locdata/part29-marcxml.tar.gz
> http://dcmi-rda.s3.amazonaws.com/locdata/part29-modsxml.tar.gz
>
> Each download is a gzipped tar containing a *set* of up to 25 xml
> files. Each of these files is a 10,000 record split of the data in the
> corresponding part. I broke each part into 10,000 record splits so I
> could process the transformations more easily.
>
> N.B. there is a bug in part 13 split 25, for some reason the marc xml
> output was incomplete so up to 10,000 records could be missing.
>
> FWIW I initially tried the conversions without splitting each
> part. I.e. I converted each original marc file into a single marc xml
> file, then tried to transform that to a mods xml file via
> xsltproc. However I found you need more than 7GB ram to do the marcxml
> to modsxml transform on a whole part (I tried it on a large ec2
> instance), so that's when I decided to split each part into smaller
> chunks, which I figured would be faster to process and more amenable
> to parallel processing (transforming all the splits from marcxml to
> modsxml took a couple of hours on a c1.xlarge ec2 instance, running up
> to 10 transformations in parallel; it can also be done on a laptop,
> but takes ~10 times longer).
>
> Btw if anyone else has experience of the marcxml->modsxml transform on
> a file of similar size do let me know, I don't do a lot of xslt-ing so
> may be missing some tricks for making it work on smaller computers.
>
> Cheers,
>
> Alistair
>
>
> On Mon, Dec 22, 2008 at 03:31:50PM -0500, Ed Summers wrote:
>   
>> Hey Alistair:
>>
>> On Mon, Dec 22, 2008 at 1:16 PM, Alistair Miles
>> <[log in to unmask]> wrote:
>>     
>>> Any tips for how I could turn these data into RDF?
>>>       
>> If you want to work specifically with that dataset you could download
>> the different parts Karen pointed you to, and convert to MARCXML using
>> an efficient tool like yaz-marcdump [2]. yaz-marcdump is nice it will
>> convert from MARC-8 to UTF-8.
>>
>> Once you've got it in MARCXML you could then use a stylesheet like
>> LC's [2] to convert to DublinCore flavored RDF. This might be kinda
>> lossy for your RDA work though, so you might want MARCXML->MODS [3],
>> and then use the MODS->RDF conversion that the Simile folks created
>> (which Karen also pointed you to) [4].
>>
>> In fact Simile used that stylesheet on their own MIT Library Catalog
>> MARC data (Barton) and still seem to have the result online [5]. So
>> perhaps just using the Barton data is the quickest way to begin
>> playing with what once was MARC data as RDF? To my knowledge Stefano
>> Mazzocchi simply created an RDF vocabulary that mirrors the  MODS XML
>> Schema, but I haven't looked at it in a while.
>>
>> Another thing worth checking out might be Rob Styles work [6] with
>> other people at Talis at converting MARC with full fidelity to RDF.
>> Perhaps he has some tools (or data) at his disposal? Rob you are on
>> here right?
>>
>> I'd be willing to lend a hand with some of this if necessary, so just
>> let me know if you think I can help.
>>
>> //Ed
>>
>> [1] http://www.indexdata.com/yaz/doc/yaz-marcdump.tkl
>> [2] http://www.loc.gov/standards/marcxml/xslt/MARC21slim2RDFDC.xsl
>> [3] http://www.loc.gov/standards/mods/v3/MARC21slim2MODS3.xsl
>> [4] http://simile.mit.edu/wiki/MARC/MODS_RDFizer
>> [5] http://simile.mit.edu/wiki/Dataset:_Barton
>> [6] http://events.linkeddata.org/ldow2008/papers/02-styles-ayers-semantic-marc.pdf
>>     
>
>   

-- 
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Karen Coyle / Digital Library Consultant
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