Matthew (01)
>
> MW: Entity (types) are the types of things you wish to hold data
> about. These can be as much verb based - actions, as noun based. So
> most companies would wish to hold data about the sales they made, for
> example. (02)
I think its considered good practice. Similar arguments would be
applicable to RDF, imho (03)
Some references quoted below (04)
[PS]
Heuristics-based entity-relationship modelling through natural ...
File Format: Adobe PostScript - View as Text
generation of Entity-Relationship (ER) diagrams for database modelling
from a ..... part of speech such as noun, verb and determiner to
reflect the word's ...
www.infm.ulst.ac.uk/~paul/pubs/omaraics04.ps - Similar pages - Note this (05)
>
2.1 Overview of Data Modelling
The first step in designing a database application is to understand
what information
the database must store. This step is known as requirements analysis.
The information
gathered in this step is used to develop a high-level description of
the data to be stored
in the database. This step is referred to as conceptual design, and it
is often carried out
using the ER model. ER models are built around the basic concepts of entities,
attributes, relationships and cardinality. An entity is an object that
exists in the real
world and is distinguishable from other objects. These are typically
derived from
nouns. Examples of entities include the following: a "student", an
"employee" and a
"book". A collection of similar entities is called an entity set. An
entity is described
using a set of attributes. The attributes of an entity reflect the
level of detail at which
we wish to represent information about entities. Attributes may be derived from
adjectives and adverbs. For example, the "Student" entity set may have
"ID_number",
"Name", "Address", "Course" and "Year" as its attributes. A relationship is an
association among two or more entities. Relationships can be typically
derived from
verbs. For example, we may have a relationship from this sentence: A student may
"take" many courses. "take" implies a relationship between the entity
"student" and
"course". Cardinality represents the key constraint in a relationship.
In the previous
example, the cardinality is said to be many-to-many, to indicate that
a student can
take many courses and a course can be taken by many students. In an ER
diagram, an
entity is normally represented by a rectangle. An ellipse usually
represents an attribute
meanwhile a diamond shape shows a relationship. Cardinality is
represented by 1 for
the one-sided and M for the many-sided. (06)
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