Introduction to metadata

Abstract:

This chapter outlines the function, history, and types of metadata used in libraries and other cultural heritage institutions. The history of library metadata, its development in relation to the evolution of information technology, and its importance to later metadata schemas is put in context. The chapter also looks at the importance of metadata to digital resources, as well as how metadata improves the discovery of resources. Types of metadata such as descriptive metadata and rights metadata are distinguished. This chapter also presents an example of Dublin Core metadata expressed in XML. Also included is a discussion of consistency and quality control. Common metadata languages are discussed, and resources for more information are listed for the most commonly used metadata languages in cultural heritage institutions.

Key words

Cataloging

metadata

discovery

descriptive metadata

administrative metadata

rights metadata

Introduction

Congratulations! If you are reading this book, you have probably decided that metadata is important to you, but you have to go about figuring how to do it. Perhaps you are starting a collection of digital images from scratch. Perhaps you have inherited a collection to curate, but the person who set up the system for metadata creation failed to leave you any documentation. You don't have the time or the funds to go to a workshop lasting a week, let alone to take a semester-long course. You need to create quality metadata NOW. My colleagues and I decided to create this metadata workbook because your plight is very common. Much of the material in this book evolved from our "Metadata Day" workshop, which we presented around New Mexico and West Texas, to cultural heritage professionals just like you. Their participation and feedback helped inform the format of this workbook.

The metadata manual: how to use

Our goal is to give the reader a flexible how-to guide, and to provide enough background and practice to understand the context and utility of several popular metadata languages. You can read the whole book in order, or pick out the chapters on metadata languages that you need to know.

If you choose to focus on specific languages, we suggest reading this chapter, to give you background and history, as well as the XML chapter before going further. Although you may not need to create metadata directly in XML, since it is the foundation of data exchange on the web, having a working knowledge of it may help you better understand and interact with data.

To begin

In this first chapter we will begin with the basics, to give you some grounding in the function of metadata before we look more closely at the specifics of the metadata languages you are most likely to need in a cultural heritage institution.

This chapter should help you:

 gain an understanding of the purpose and utility of metadata;

 learn about the history of metadata development;

 understand why metadata is vital in the digital world;

 learn the vocabulary associated with some of the most common metadata languages and understand when you would want to use them;

 know where to find more information.

What is metadata?

An often-quoted definition of metadata is "data about data." This is a literal definition, but perhaps not the most illuminating. In 2004, the National Information Standards Organization (NISO) defined metadata as "structured information that describes, explains, locates, or otherwise makes it easier to retrieve, use, or manage an information resource" (NISO, 2004, p. 1).

The Federal Geographic Data Committee (FGDC), in its "Business Case for Metadata," has a helpful description of metadata. Although it focuses on geographic information, the statement applies to all metadata:

Metadata helps people who use [geospatial] data find the data they need and determine how best to use it. Metadata supports producers in locating and using their own data resources and data consumers in locating and using data resources produced by others. (FGDC, 2012)

Try to think of metadata as a piece of information describing a resource. It's like the nutritional information on a package of food ? metadata is the information about what's inside the package. You can also think of the information that you enter into a social networking site such as Facebook or LinkedIn as metadata about yourself. Metadata can describe a wide variety of information, such as:

 the subject matter of the resource;

 the creators of the resource;

 the technical information needed to store and access the resource;

 the legal rights to the resource.

Metadata can be used to find, gather, and maintain resources over long periods of time. Think about all the information that a user will need to know whether the resource meets their needs and whether and how they can use it. Metadata can tell you what the information is about, how to use it, whether you need permission to use it, and where to get that information. Metadata makes web searching more meaningful. It helps you promote your resources, reach the right audience, and make connections between related resources.

Another question about metadata: Why do it? After all, there are powerful search engines readily available and many resources are full-text searchable. However, many resources are not text. Image files would be undiscoverable on the web without textual metadata describing the image. Even in a text resource, some important information may not be easily available. The author may not be clearly stated, or the sponsoring institution, or the copyright owner. All are areas of sufficient concern for libraries and cultural heritage institutions to justify metadata production.

Unfortunately, metadata is often perceived as being a fussy, labor-intensive, unnecessary step in data management. Lynda Wayne of the FGDC identifies the perceived major obstacles to metadata creation (Wayne, 2005, p. 1):

 Metadata standards are too expensive and difficult to implement.

 Metadata production requires time and other resources.

 There are few immediately tangible benefits and incentives to produce metadata.

These perceptions require that we make metadata creation as efficient as possible, promote the benefits of metadata, and publicize results. Time and care at the stage of creating workflows will pay off when you can report how impact on workload is reduced. Promotion of metadata shouldn't end with the creation of metadata, but we need to keep telling our administrations and resource providers how metadata is increasing visibility of collections. Keeping statistics on the usage of the collection, especially if you have pre- and post-metadata enrichment figures, can make a compelling case.

History of metadata

Metadata, by any other name, has been around as long as libraries and archives. Library cataloging is descriptive metadata. The earliest catalogs were "dictionary catalogs"? manuscript or printed volumes with entries describing the material in the collection. Any inventory of books, documents, or objects could be considered descriptive metadata. As collections grew, these inventories needed to become more systematized. Understanding some background and history of library cataloging evolution can be helpful in knowing where some metadata conventions have their roots, and why there are so many metadata "crosswalks" involving library standards.

"Classic" library cataloging, which dates back to antiquity, was primarily focused on description of content. Cataloging described the creator of the resource (usually a book), the title, the physical characteristics of the resource, and the subject matter. The dictionary catalogs of earlier centuries evolved into card catalogs as libraries grew, providing an easy way to file more titles without having to republish the catalog too frequently. Subject analysis also became necessarily more complex. The amount of information in collections was growing, so organizing the material for browsing became a more complicated task.

While there were many predecessor systems for creating library cataloging, the most ubiquitous today is the pairing of MARC 21 and AACR2 - the Anglo-American Cataloging Rules, revision 2, expressed in MAchine-Readable Cataloging tags. This is the cataloging you see in most Integrated Library Systems (ILSs), and up until very recently was the only metadata standard in them. The first edition of AACR was published in 1967, and there were major revisions in 1978, 1988, and 2002, with many updates in between revisions. MARC was developed in the 1960s and became an international standard in 1973. MARC was necessary because, while descriptions, subject analysis, and classification could exist in dictionaries or on cards in "naked" form, albeit in an...