Metadata Standards

Digital Libraries are all about Metadata.  You can think of metadata fields as the parts that should be filled out for each record in an electronic card catalog.  The thing about metadata though is that it is a nebulous concept that would be difficult to share without a bit of additional structure.

To provide this structure, multiple organizations have issued sets of metadata standards to help organizations create and share records.

Primary among these (in educational circles) is the Dublin Core standard issued by the Dublin Core Metadata Initiative (DC and DCMI respectively).  DC defines a standard set of fields to describe objects.  While there are other formats that also do this (IEEE’s Learning Object Metadata for one), DC is by far the most widely implemented.

One of the reasons DC is so widely implemented is that it is very easy.  There are only a few core fields that should be filled in (Title, Description, Creator, etc.), although there are many optional fields to help describe resources in depth.  Additionally, there is no hierarchy in the XML (for base fields), which simplifies matters for the non-technical.  Finally, it is extensible.  This is important so that the institutions with technical expertise can customize it with qualified vocabularies and specialized fields to fit their needs.

Another reason DC is so widely implemented is that it is the only format required by repositories supporting the Open Access Initiative Protocol for Metadata Harvesting (OAI-PMH), most commonly referred to as OAI.  As nearly all archives interested in sharing metadata records support this standard, DC has become the lingua franca among educational digital libraries.

Here is an example of 4 fields from a very simple DC record:

  <dc:title>The Oklahoma Daily</dc:title>
  <dc:description>OU's campus newspaper.</dc:description>
  <dc:publisher>University of Oklahoma</dc:publisher>
  <dc:identifier>http://oudaily.com/</dc:identifier>

If you ignore the dc: stuff, you’ll see that it’s just a way of storing the title, description, publisher, and location of the object. By defining these things in predictable ways, computers can automate the exchange of these records.

When you’re talking about exchanging millions of records, like the NSDL does, that becomes quite important.

Next time I’ll talk a bit more about controlled vocabularies and qualified metadata standards.

A few digital collections of note

I’d like to highlight three collections that I find outstanding.

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1. The first is the Prelinger Archives, an archive of “ephemeral” films having historic significance. Included in the archives are sets of commercial and government propaganda films shown to school children in the 40s and 50s.

I consider it to be a premier example of a digital library preserving material that would otherwise be lost.

While there are many videos of note in this collection, 3 short films stand out to me:

• Despotism – This short film from 1946 is one of my favorite films. It explains how sales taxes hit the poor harder than income taxes, why limitations were originally put on media consolidation, and even has a example of citizens reciting the Pledge of Allegiance from before “under God” was added in the 1950s.

  I only wish more of the following generation had taken the lessons taught in this video to heart.

• Duck and Cover – This 1951 film from the U.S. government uses an illustrated turtle to explain the secret to avoiding nuclear weapons.

  This film is widely referred to in popular culture and is sometimes used as an example of how the U.S. government over-simplified the dangers of nuclear war.

• In Our Hands, Part 1: How we got what we have – While I can’t in good conscience tell you to watch the entire film, the 11:23 to the 12:48 minute mark is required viewing for anyone interested in understanding how Native Americans were viewed in the 50s.

All films are available in the public domain making them perfect specimens for remixes and classroom airings.

The Prelinger Archives are a part of the Internet Archive, which I strongly suggest everyone examine. Of particular interest is the Archive’s Wayback Machine (try this search for CNN’s front page). I know multiple people that were surprised upon learning that their personal website/blog from 10 years ago was still stored in the archive despite their deletion of those pages/posts later.

2. A second collection that I would like to note is Librivox.

I became aware of this collection because my wife enjoys listening to audiobooks during her commute to Oklahoma City. Unfortunately, our local library does not have the resources to keep up with her voracious listening habits and purchasing audiobooks is prohibitively expensive.

Enter Libervox – a collection of free audio books of public domain works contributed by parties from around the world.

Audiobooks are available in their catalog covering everything from Aesop’s Fables to Pride and Prejudice. Additionally, they have an active user community so that you may read a chapter for a book if you want to give back.

Libervox gets most of its works from Project Gutenburg and the Internet Archive. Hopefully you’re familiar with Project Gutenburg as it offers over 25,000 free works in the public domain. If you’re unfamiliar, take a look.

3. Finally, I would be remiss if I didn’t include at least one educational digital library. In particular, I’d like to highlight On the Cutting Edge. This digital library of learning objects is targeted at professional development for geoscience faculty.

I like this digital library mostly because it has one of the most fluid faceted classification browsing mechanisms I’ve seen integrated into a keyword search (INSPEC is also awesome). To get a feel for it, check out this search for lava. The developers of this digital library have also published an article in D-Lib on their use of controlled vocabularies on search pages to create this type of faceted browse.

On the Cutting Edge is part of the Science Education Resource Center.

While there are many other digital collections out there, these three collections have shown me what can be possible if you have interested communities.

Cited Article

Fox, S., Manduca, C. A., Iverson, E. 2005. Building Educational Portals atop Digital Libraries. D-Lib 11 (1).

Introduction

About this blog

This blog will discuss the issues that arise during the development of digital libraries today. While the blog may occasionally delve into theoretical questions, its primary focus will be on the integration of new features into digital collections.

About me

Qualifications to write this blog

Since 2002 I have worked on comPADRE, a digital library of physics and astronomy educational resources for the American Association of Physics Teachers. In 2005, comPADRE was recognized as an integral part of the National Science Digital Library and became a Pathway. Around that time I also became comPADRE’s Technical Lead.

During the past six years of building a digital library from scratch, I’ve confronted issues dealing with everything from usability and web design to privacy policies and information architecture and security. I am hopeful that my experiences can help others as they work on digital libraries.

Background

I was raised in Louisiana and Mississippi and am rather laid back in person. I can probably be quite brusque online though.

I bounced around quite a few schools growing up, but my junior and senior years of high school were spent at the Mississippi School for Mathematics and Science (MSMS).  I was a National Merit Scholar and decided to take the University of Oklahoma up on its full ride.  I eventually graduated with a BA in Mathematics and a Physics minor.

Previous to working for comPADRE, I worked as a computer programmer for various instant messaging and educational companies in Oklahoma and Washington, DC.

My first years with comPADRE were spent working primarily as a programmer.  However, I developed a personal interest in the theory behind the library structures I was implementing and eventually decided to pursue an MLIS at the University of Oklahoma’s School of Library and Information Studies. Since 2005, I have worked approximately 30 hours a week for comPADRE while taking courses.  My graduation is currently slated for December 2009.

Other interests

I have a passion for ancient history, particularly Greek and Roman, and I know some Latin and Ancient Greek.  I consume media voraciously and read a lot of sci-fi, fantasy, historical fiction, and comics.  I spend quite a bit of time online and thinking about politics as well.  These interests should rarely bleed into this blog however.