Data management

Archiving Ipswich

Two years after posting about my work on the Silbury Hill digital archive, in ‘AN ADS DAY OF ARCHAEOLOGY’, and I’m still busy working as a Digital Archivist with the ADS!

For the past few months, I have been working on the Ipswich Backlog Excavation Archive, deposited by Suffolk County Council, which covers 34 sites, excavated between 1974 and 1990.

Ipswich2

Excavation at St Stephen’s Lane, Ipswich 1987-1988

To give a quick summary of the work so far, the data first needed to be accessioned into our systems which involved all of the usual checks for viruses, removing spaces from file names, sorting the data into 34 separate collections and sifting out duplicates etc.  The archive packages were then created which involved migrating the files to their preservation and dissemination formats and creating file-level metadata using DROID.  The different representations of the files were linked together using object ids in our database and all of the archiving processes were documented before the coverage and location metadata were added to the individual site collections.

Though time consuming, due to the quantity of data, this process was fairly simple as most of the file names were created consistently and contained the site code.  Those that didn’t have descriptive file names could be found in the site database and sorted according to the information there.

The next job was to create the interfaces; again, this was fairly simple for the individual sites as they were made using a template which retrieves the relevant information from our database allowing the pages to be consistent and easily updateable.

The Ipswich Backlog Excavation Archive called for a more innovative approach, however, in order to allow the users greater flexibility with regards to searching, so the depositors requested a map interface as well as a way to query information from their core database.  The map interface was the most complex part of the process and involved a steep learning curve for me as it involved applications, software and code that I had not previously used such as JavaScript, OpenLayers, GeoServer and QGIS.  The resulting map allows the user to view the features excavated on the 34 sites and retrieve information such as feature type and period as well as linking through to the project archive for that site.

OpenLayers map of Ipswich excavation sites.

OpenLayers map of Ipswich excavation sites.

So, as to what I’m up to today…

The next, and final step, is to create the page that queries the database.  For the past couple of weeks I have been sorting the data from the core database into a form that will fit into the ADS object tables, cleaning and consolidating period, monument and subject terms and, where possible, matching them to recognised thesauri such as the English Heritage Monument Type Thesaurus.

Today will be a continuation of that process and hopefully, by the end of the day, all of the information required by the query pages will be added to our database tables so that I can begin to build that part of the interface next week.  If all goes to plan, the user should be able to view specific files based on searches by period, monument/feature type, find type, context, site location etc. with more specialist information, such as pottery identification, being available directly from the core database tables which will be available for download in their entirety.  Fingers crossed that it does all go to plan!

So, that’s my Day of Archaeology 2015, keep a look out for ADS announcements regarding the release of the Ipswich Backlog Excavation Archive sometime over the next few weeks and check out the posts from my ADS colleagues Jo Gilham and Georgie Field!

Something old and something new: CAD migration and archive accessioning at ADS

ADSeasy-250x250As a reasonably new face at the Archaeology Data Service (ADS) I am still getting to grips with the somewhat baffling world of digital archiving and preservation! If someone had asked me this time last year when I was graduating what I saw myself doing in one year’s time, I would probably not have said doing a mass CAD file migration… But being a Digital Archivist for the ADS has so far been a fabulous experience.

Today I am working on two tasks, archiving collections coming through ADS-easy (for more information about ADS-easy see Ray Moore’s post from the Day of Archaeology in 2014 ), and continuing the ADS’ preservation work by migrating our historic CAD files.

It has been just over a year since the first ADS-easy archive was released, and a lot has happened in a year! For those who have not heard about ADS-easy, it is a system that allows users to electronically submit archaeological archives, along with metadata (information describing the files). It has significantly altered the workflow of digital archivists at the ADS as data from ADS-easy does not require manual inputting of metadata. Since last July we have worked on 71 archives, ranging from image collections, to excavation reports, to geophysical data. We have had 6636 unique visitors to the website and have an average of 250 unique visitors per month. Most of those are from the UK but visitors come from all over the world, including the US, Germany, Italy, France, and Spain. On average 8 archives are submitted each month and the number has been gradually rising.

ADS-Easy

Screenshot from The Grand Western Canal archive, submitted through ADS-easy (dx.doi.org/10.5284/1031512)

My role within ADS-easy is to take the data we receive, accession it into our collections management system, convert the files into suitable preservation and dissemination formats- and document all of these processes!  Finally, I create an interface so that people can see the files on the ADS website. Today I am working on an image collection from a building recording of farm buildings in Lanchester, County Durham, and a data archive from an excavation in Crowle, Worcestershire. The data that comes in from ADS-easy is varied and often comes from small scale projects that would not otherwise be shared with the public. That is what makes the job both interesting and somewhat rewarding.

That has taken me up to lunch time, this afternoon I am carrying on with the long-running task of migrating all of our historic CAD files. Data that is archived at the ADS is continually ‘preserved’ over time to ensure that it is always readable and useable, and does not become obsolete. We are in the process of migrating our CAD files from earlier versions to the more recent 2010/2011 version. This has so far involved manually going through each collection containing CAD drawings and checking each file, converting them to the 2010 version, and then moving the previous versions to a migration folder. Another part of this process is creating a PDF file of each drawing to make them accessible to people who don’t own CAD software. All of this then needs to be documented in our collections management system so that the rest of the digital archivists know what I have done to the files, and where to find them if anything goes wrong!  After this the interfaces need updating to include the new PDF files.

CAD_example

Example of one of the many CAD plans the ADS holds. From Elizabeth House (dx.doi.org/10.5284/1008432)

CAD migration may seem quite a repetitive task, but it has allowed me to look back at some of the earliest ADS collections, such as the excavations at Eynsham Abbey in the late 80s/ early 90s, and the survey and excavation at the Iron Age emporium of Vetren . This process of migration is a very important part of what the ADS does; active management of our data means that it should (in theory!) always be accessible to the public in the most useful file formats and have longevity.

Better get back to it, those remaining 1000(ish) CAD files won’t migrate themselves!

Now where did I put that data?

For someone who has been tasked with helping my team improve how we look after the data from our archaeological research, it’s a sad state of affairs that I just spent a half hour trying to find my Day of Archaeology login details. As I failed to take part last year; this means a small piece of information from just 2 short years ago was nearly lost for good. Not necessarily the most important piece of data, but it does go to show that if you do not look after data at best you waste time trying to find it, and at worst it will be lost for good. Repeating research is not a luxury that archaeologists typically have; usually it is impossible (you can’t re-dig a site), and even if you could it’s not cost effective to pay to do the work twice, so we have to make sure we are looking after it and when the time comes others can use it.

So until I spent a half hour looking for my password and login details, this is what I’ve spent most of my Day of Archaeology doing.

Our project is called Archaeological Data Archiving Protocol (ADAPt), my organisation English Heritage likes its acronyms (the less said about that the better). However, as acronyms go ADAPt is a pretty appropriate name as it is what we need to have happen. We can no longer count on our archives team to just swoop in at the end of projects and pull it together into a sensible set of files and collection of boxes to be submitted with a report to the local museum. In the digital age data management and care must be a shared responsibility from the beginning of all of research by the whole team.

I hope I’ve convinced you; now just to convince the rest of my team to do the work, on top of all of their other responsibilities.

Wish me luck,

Hugh

An ADS Day of Archaeology

Here it is, my Day of Archaeology 2013 and after a routine check of my emails and the daily news I’m ready to begin!

Silbury Hill ©English Heritage

Silbury Hill ©English Heritage

I am currently approaching the end of a year-long contract as a Digital Archivist at the Archaeology Data Service in York on an EH-funded project to prepare the Silbury Hill digital archive for deposition.

For a summary of the project, see the ADS newsletter and for a more in-depth account of my work so far check out my blog from a couple of weeks ago: “The Silbury Hill Archive: the light at the end of the tunnel”

Very briefly, though, my work has involved sifting through the digital data to retain only the information which is useful for the future, discarding duplicates or superfluous data; sorting the archive into a coherent structure and documenting every step of the process.

The data will be deposited with two archives: the images and graphics will go to English Heritage and the more technical data will be deposited with the ADS and as the English Heritage portion of the archive has been completed it is time for the more technical stuff!

So, the plan for today is to continue with the work I have been doing for the past few days: sorting through the Silbury Hill database (created in Microsoft Access).

Originally, I had thought that the database would just need to be documented, but, like the rest of the archive, it seems to have grown fairly organically; though the overall structure seems sound it needs a bit of work to make it as functional as possible and therefore as useful as possible.

The main issue with the database is that there are a fair amount of gaps in the data tables; the database seems to have been set up as a standard template with tables for site photography, contexts, drawings, samples, skeletal remains and artifact data etc.  but some of these tables have not been populated and some are not relevant.  The site photography and drawing records have not been entered for example, meaning that any links from or to these tables would be worthless.  The missing data for the 2007 works are present in the archive, they are just in separate Excel spreadsheets and there are also 2001 data files, these are in simple text format as the information was downloaded as text reports from English Heritage’s old archaeological database DELILAH.  The data has since been exported into Excel, so, again to make the information more accessible, I’m adding the 2001 data to the 2007 database.

My work today, therefore, as it has been for the past couple of days, is to populate the empty database tables with the information from these spreadsheets and text files and resolve any errors or issues that cause the tables to lose their ‘referential integrity’, for example where a context number is referred to in one table but is missing from a linking table.

Silbury database relationship diagram ©English Heritage

Silbury database relationship diagram ©English Heritage

So, this morning I started with the 2001 drawing records. The entering of the data itself was fairly straightforward, just copying and pasting from the Excel spreadsheet into the Access tables, correcting spelling errors as I went.  Some of the fields were controlled vocabulary fields, however, which meant going to the relevant glossary table and entering a new term in order for the site data to be entered as it was in the field.

Once the main drawing table was completed, the linking table needed to be populated; again, this was done fairly simply through cutting and pasting from Excel.

The next step was the most time-consuming: checking the links between the tables, to do this I went to the relationship diagram, clicked on the relevant link and ticked the box marked ‘enforce referential integrity’ this didn’t work which meant that a reference in one table was not matched in the linking table which meant going through the relevant fields and searching for entries that were not correct.  The most common reason for these error messages was that an entry had been mis-typed in one of the tables.

That took me up to lunchtime, so what about the afternoon?  More of the same: starting work on the sample records with the odd break for tea or a walk outside to save my eyes!

As much as the process of updating the database has been fairly routine, it’s an interesting and valuable piece of work for me as it is the first time I’ve ever really delved into the structure of a database and looking at the logic behind its design.  I was fortunate in that I had attended the Database Design and Implementation module taught by Jo Gilham as part of the York University Msc in Archaeological Information Systems which gave me a firm foundation for this work.  Also very helpful was the help provided by Vicky Crosby from English Heritage who created the database and provided a lot of documentation in the first instance.

The next step once the data has been entered will be to remove any blank fields and tables and then to document the database using the ADS’ Guidelines for Depositors and then to move on to the survey data and reports.

I’m looking forward to seeing it all deposited and released to a wider world for, hopefully, extensive re-use and research!