Re: Def: Data Model

an attempted refinement..

Data Model (WC):

The way that information is organised. For example, a database might contain
information about a customer, classified as an address, a name, a birthdate,
and a picture. A web page might contain a list of lists, where each sub-list
contains (in order) a family name, an initial, a street, a city, and a URI.
These data models are slightly different, but so long as the model is
explicit about what things are represented it is often posssible for either
people (using their own knowledge) or computers (using technologies like XML
schema) to do sensible conversions or comparisons between information using
different data models.

An explicit data model also helps a user to provide a personalised
presentation.

........
Charles McCN

On Thu, 21 Dec 2000, Katie Haritos-Shea wrote:

  As per today's discussion, we need to define Data Model.  Below is a start,
  please review and rip it apart for better
  comprehension.........................

  Data Model WC The product of the database design process which aims to to
  identify and organize the required data logically and physically. A data
  model says what information is to be contained in a database, how the
  information will be used, and how the items in the database will be related
  to each other. For example, a data model might specify that a customer is
  represented by a customer name and credit card number and a product as a
  product code and price, and that there is a one-to-many relation between a
  customer and a product. It can be difficult to change a database layout once
  code has been written and data inserted. A well thought-out data model
  reduces the need for such changes. Data modelling enhances application
  maintainability and future systems may re-use parts of existing models,
  which should lower development costs. A data modelling language is a
  mathematical formalism with a notation for describing data structures and a
  set of operations used to manipulate and validate that data. One of the most
  widely used methods for developing data models is the entity-relationship
  model. The relational model is the most widely used type of data model.
  Another example is NIAM.


  Katie Haritos-Shea
  508 Coordinator / Webmaster, CIW
  NTIS/Fedworld
  Department of Commerce
  5285 Port Royal Road
  NTIS WebLab for Accessible Design
  Room  # 2025
  Springfield, Virginia, 22161
  ph 703-605-6426  fax 703-605-6826
  mailto:kshea@fedworld.gov
  mailto:kshea@ntis.fedworld.gov




-- 
Charles McCathieNevile    mailto:charles@w3.org    phone: +61 (0) 409 134 136
W3C Web Accessibility Initiative                      http://www.w3.org/WAI
Location: I-cubed, 110 Victoria Street, Carlton VIC 3053, Australia
until 6 January 2001 at:
W3C INRIA, 2004 Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex, France

Received on Friday, 22 December 2000 09:06:12 UTC