Introduction
We often hear the phrase "information is power", but with increasing amounts of data being created and stored (but often not well organised) there is a real need to document the data for future use - to be as accessible as possible to as wide a "public" as possible. There are significant benefits in doing so:
The term metadata has become widely used over the past 15 years, and has become particularly common with the popularity of the World Wide Web. But the underlying concepts have been in use for as long as collections of information have been organised. Library catalogues represent an established variety of metadata that has served for decades as collection management and resource discovery tools. The concept of metadata is also familiar to most people who deal with spatial issues. A map legend is one representation of metadata, containing information about the publisher of the map, the publication date, the type of map, a description of the map, spatial references, the map's scale and its accuracy, among other things. Metadata are also these types of descriptive information applied to a digital geospatial file. They're a common set of terms and definitions to use when documenting and using geospatial data. Most digital geospatial files now have some associated metadata. In the area of geospatial information or information with a geographic component this normally means the What, Who, Where, Why, When and How of the data. The only major difference that therefore exists from the many other metadata sets being collected for libraries, academia, professions and elsewhere is the emphasis on the spatial component - or the where element.
The Benefits of Metadata
etadata helps people who use geospatial data find the data they need and determine how best to use it. Metadata benefit the data-producing organisation as well. As personnel change in an organisation, undocumented data may lose their value. Later workers may have little understanding of the contents and uses for a digital database and may find they can't trust results generated from these data. Lack of knowledge about other organisations' data can lead to duplication of effort. It may seem burdensome to add the cost of generating metadata to the cost of data collection, but in the long run the value of the data is dependent on its documentation.
etadata is one of those terms that is conveniently ignored or avoided. However there is an increasing recognition of the benefits and requirement for metadata for our data as we continue to increase the use of digital data. Whereas cartographers rigidly provided metadata within a paper map's legend, the evolution of computers and GIS has seen a decline in this practice. As organisations start to recognize the value of this ancillary information, they often begin to look at incorporating metadata collection within the data management process.
A number of studies have established that although the value of geospatial data is recognised by both government and society, the effective use of geospatial data is inhibited by poor knowledge of the existence of data, poorly documented information about the data sets, and data inconsistencies. Once created, geospatial data can be used by multiple software systems for different purposes. Given the dynamic nature of geospatial data in a networked environment, metadata is therefore an essential requirement for locating and evaluating available data. Metadata can help the concerned citizen, the city planner, the graduate student in geography, or the forest manager find and use geospatial data, but they also benefit the primary creator of the data by maintaining the value of the data and assuring their continued use over a span of years. Twenty-five years ago, humans landed on the Moon. Data from that era are still being used today, and it is reasonable to assume that today's geospatial data could still be
used in the year 2020 and beyond to study climate change, ecosystems, and other natural processes. Metadata standards will increase the value of such data by facilitating data sharing through time and space. So when a manager launches a new project, investing a small amount of time and resources at the beginning will pay dividends in the future.Context and Rationale
The word metadata shares the same Greek root as the word metamorphosis. "Meta-" means change and metadata, or "data about data" describe the origins of and track the changes to data. Metadata is the term used to describe the summary information or characteristics of a set of data. This very general definition includes an almost limitless spectrum of possibilities ranging from human-generated textual description of a resource to machine-generated data that may be useful to software applications.
Chapter Three | Context and Rationale | Organisational Approach | Implementation Approach