UKOLN AHDS Metadata Deployment


This document describes the issues you will need to address in order to ensure that you make use of appropriate approaches for the deployment of metadata within your project.

Why Do You Wish To Use Metadata?

The first question you should address is "Why do you wish to use metadata?". You may have heard that metadata is important. You may have heard that metadata will help solve many problems you have with your project. You may have heard that others are using metadata and you don't wish to be left behind. Although all of these points have some validity, they are not sufficient in isolation to justify the time and effort needed in order to deploy metadata effectively.

You should first specify the problem you wish to address using metadata. It may be that you wish to allow resources on your Web site to be found more easily from search engines such as Google. It may be that you wish to improve local searching on your Web site. It may be that you wish to interoperate with other projects and services. Or it may be that you wish to improve the maintenance of resources on your Web site. In all of these cases metadata may have a role to play; however different approaches may be needed to tackle these different problem and, indeed, approaches other than use of metadata may be more effective (for example, Google makes only limited use of metadata so an alternative approach may be needed).

Identifying The Functionality To Be Provided

Once you have clarified the reasons you wish to make use of metadata you should identify the end user functionality you wish to provide. This is needed in order to define the metadata you will need, how it should be represented and how it should be created, managed and deployed.

Choosing The Metadata Standard

You will need to choose the metadata standard which is relevant for your purpose. In many cases this may be self-evident - for example, your project may be funded to develop resources for use in an OAI environment, in which case you will be using the OAI application.

Metadata Modelling

It may be necessary for you to decide how to model your metadata. For example if you wish to use qualified Dublin Core metadata you will have to chose the qualifiers you wish to use. A QA Focus case study illustrates the decision-making process [1].

Metadata Management

It is important that you give thought to the management of the metadata. If you don't you are likely to find that your metadata becomes out-of-date. Since metadata is not normally displayed to end users but processed by software you won't even be able to use visual checking of the metadata. Poor quality metadata is likely to be a major barrier to the deployment of interoperable services.

If, for example, you embed metadata directly into a file, you may find it difficult to maintain the metadata (e.g. the creator changes their name or contact details). A better approach may be use of a database (sometimes referred to as a metadata repository) which provides management capabilities.

Example Of Use Of This Approach

The Exploit Interactive [2] e-journal was developed by UKOLN with EU funding. Metadata was required in order to provide enhanced searching for the end user. The specific functionality required was the ability to search by issue, article type, author and title and by funding body. In addition metadata was needed in order to assist the project manager producing reports, such as the numbers of different types of articles. This functionality helped to identify the qualified Dublin Core elements required.

The MS SiteServer software used to provide the service provided an indexing and searching capability for processing arbitrary metadata. It was therefore decided to provide Dublin Core metadata stored in <meta> tags in HTML pages. In order to allow the metadata to be more easily converted into other formats (e.g. XHTML) the metadata was held externally and converted to HTML by server-side scripts.

A case study which gives further information (and describes the limitations of the metadata management approach) is available [3].


  1. Gathering the Jewels: Creating a Dublin Core Metadata Strategy, QA Focus,
  2. Exploit Interactive,
  3. Managing And Using Metadata In An E-Journal, QA Focus,