Metadata

Quiz 5.1

is pervasive in information systems, and comes in many forms. The core features of most software packages we use every day are metadata-driven. 

Metadata

Metadata

__________ is a set of data that describes and gives information about other data.
“__________ is a structured information that describes, explains, locates or otherwise makes it easier to retrieve, use and manage an information resource.”
__________ describes how and when and by whom a particular set of data was collected, and how the data is formatted.
__________ is defined as the data providing information about one or more aspects of the data; __________ is used to summarize basic information about data which can make tracking and working with specific data easier.
__________ is data in data warehouse, to represent other data.
Or, __________ is data about data.
__________ is summarized data that leads to detailed data.
__________ is a roadmap about data warehouse.
Created for the data names and definition of a given data warehouse.
Acts as a directory to help the decision support system to locate the content of a data warehouse.

Metadata

key to the functionality of the systems holding the content, enabling users to find items of interest, record essential information about them, and share that information with others.

find data, use data, and preserve and re-use data in the future.

Metadata is created and collected because it enables and improves use of that data. Metadata ensures that we will be able

Image

An ______ may include metadata that describes how large the picture is, the colour depth, the image resolution, when the _____ was created, and other data.

text document

This metadata may contain information about how long the document is, who the author is, when the document was written, and a short summary of the document.

Web pages

_____ often include metadata in the form of meta tags. Description and keywords meta tags are commonly used to describe the Web page's content.

manually, or by automated information processing

Metadata can be created?

Resource discovery

Functions of Metadata

Allowing resources to be found by relevant criteria;

• Identifying resources;

• Bringing similar resources together;

• Distinguishing dissimilar resources;

• Giving location information.

Organizing e-resources

Functions of Metadata

• Organizing links to resources based on audience or topic.

• Building these pages dynamically from metadata stored in databases.

Facilitating interoperability

Functions of Metadata

• Elements for standard number, e.g. ISBN.

• The location of digital object may also given using :
  • A file name
  • A URL

Archiving and preservation

Functions of Metadata

• Digital information is fragile and can be corrupted or altered;

• It may become unusable as storage technologies change.

• Metadata is key to ensuring that resources will survive and continue to be accessible into the future. Archiving and preservation require special elements:

  • to track the lineage of a digital object,

  • to detail its physical characteristics, and

  • to document its behaviour in order to emulate it in future technologies.

Bretherton & Singley (1994)

distinguished between two distinct classes: structural/control metadata and guide metadata.

Structural metadata

• describes the structure of database objects such as tables, columns, keys and indexes.

Guide metadata

• helps humans find specific items and are usually expressed as a set of keywords in a natural language.

Ralph Kimball

Divided metadata into 2 similar categories: technical metadata and business metadata.

Technical metadata

• corresponds to internal metadata

business metadata

corresponds to external metadata.

Descriptive metadata

is typically used for discovery and identification, as information to search and locate an object, such as title, author, subjects, keywords, publisher.

Structural metadata

describes how the components of an object are organized. An example of structural metadata would be how pages are ordered to form chapters of a book.

Administrative metadata

gives information to help manage the source. Administrative metadata refers to the technical information, including file type, or when and how the file was created and who can access it.

Business metadata

 Contains the data ownership information,.
 Business definition
 Changing policies.
 Source system name and description
 Report name and description
 Obtained from business users 

Operation metadata

It include currency of data and data lineage.
 Currency of data means whether the data is active ,achieved or purged.
 Lineage of data means the history of data migrate and transformation on it

Technical metadata

Includes database system names, table and column names and size, data types and allowed values.
 Includes structural information such as primary key and foreign key attribute and indices.

Role of metadata

 Act as directory.
 Directory helps decision support system to allocate the content of data warehouse.
 Helps in mapping of data when data transformed from operational environment to data warehouse environment.

 Helps in summarization between current detailed data and highly summarized data.
 used as query tools
 Used as reporting tools.
 Used as extraction and cleaning tools.

Title/Name

Metadata Elements

Name given to the resource.

Description

Metadata Elements

A description of the resource and its spatial, temporal or subject coverage.

Format

Metadata Elements

File format, physical medium, dimensions of the resource, or hardware and software needed to access the data.

Metadata

Metadata Elements

Description of the metadata to be provided along  with the generated data and a discussion of the metadata standards used, including the version of the schema and where the schema can be found.

Identifier

Metadata Elements

A unique identification assigned to the resource.

Rights Holder

Metadata Elements

The entities or persons who hold the rights to the data.

Rights

Metadata Elements

Information about the rights held in and over the resource.

Contact Information

Metadata Elements

Identity of, and means to communicate with persons or entities associated with the data.

standardized

In order to be useful, metadata needs to be________. This includes agreeing on language, spelling, date format, etc. If everyone uses a different standard, it can be very difficult to compare data to other data.

schema

A key component of metadata is the

Metadata schemes

are the overall structure for the metadata. It describes how the metadata is set up, and usually addresses standards for common components of metadata like dates, names, and places. There are also discipline-specific schemas used to address specific elements needed by a discipline.