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Understanding the Data Model
The following are the key concepts and terms in the National Education Data Model.
Data Model Top-Level Classes
In the Data Model Browser, the Data Model content is arranged in a tree-type structure.
There are ten top-level classes (or branches) of the tree. On the Data Model Browser
screen, the list on the left of the allows the user to “drill down” into the subclasses
that are below each top-level class.
A class is, “A set, collection, group, or configuration containing members regarded
as having certain attributes or traits in common; a kind or category.” To distinguish
between entities and classes the Data Model uses a capital first letter in the names
of classes while entity names begin with a lower-case letter. For example a Person
is a class while a staffMember is an entity. The figure below illustrates the relationships
between the concepts. Entities, which identify what needs to be tracked by education
systems, are organized into classes and sub-classes. Each entity may have attributes,
which represent the measures are used to track the entity. In the Data Model, entities
may relate to other entities.
An entity is the basic building block of the Data Model. Entities are the constructs
that need to be tracked, measured, and described by software systems in order to
support education processes. Entities can be:
- Persons such as students, parents, or staff members.
- Capital Assets such as schools, school busses, or buildings
- Events such as test administrations, class meetings, or discipline
- Tools such as books, networks, computers, lessons, or assessments
- Concepts such as perceptions or skills
An attribute is information about an entity that you can measure, classify, or describe.
An attribute is not a calculation or statistic, and it generally does not contain
counts. Attributes in the Data Model are generally not generic measures or data
elements that can connect to a number of entities. In the Data Model, each attribute
is designed to be unique to the entity that it measures. Common Attributes are an
exception to this rule.
Some examples of attributes include:
- A measurement, current state, or a trait of an entity
- A person’s name, phone number, or IM address
- An education institution’s name, location, or size
- The date of a test administration, the value of an assessment score
- Lesson’s topic, grade level, or student’s learning style
- A teacher’s self efficacy with respect to classroom management
4. Common Attributes
Attributes are usually specific to each entity. However, a small set of attributes
exist that apply to multiple entities. These attributes are referred to as common
attributes and are arranged into a taxonomy below. This taxonomy of common attributes
should not be confused with the Data Model taxonomy of entities.
This limited set of Common Attributes are included for the sake of consistency of
definition and to promote uniformity in the specification of attributes. The common
attributes are expected to change as the Data Model continues to be updated with
the most up-to-date set of descriptors. Items lower in the hierarchy are more specific
than those above. Items at any level in the hierarchy may be associated with an
- First Name
- Former Legal Name
- Generation Code/Suffix
- Last/Surname at Birth
- Middle Name
- Physical Location
- Physical Address
- GPS Coordinates
- Virtual Location
- IP Address
- Postal Address
- Connection Id
- e-mail Address
- Phone Number
- Screen Name
- IM address
- Physical Characteristic
- IEEE LOM
- Dublin Core
- Resources Consumed
- Financial Resources
- Time Resources
- Human Resources
- Curricular Resources
- Instructional Materials
- New Technology Resources Used
- Equipment Used
- Supplies Used
- Facilities Resources
- Number of Buildings
- Square Feet
- Measurable Goals and Outcomes
- Academic Goals
- Academic Achievement
- Skills Acquisition
- Skill Certification
- Non-Academic Goals
- Health Effects
- Social Effects
- Participation Effects
- Goal-Based Outcomes
- Target/Served Population
- Program Baselines
- Method of Identification
- Population Characteristics
- Program Availability
- Length of Program
- Periodicity of Service
- Length of Services
- NCES Program Type
- Delivery Methodology
- Inquiry Based
- Directed Instruction
In addition to the taxonomy structure (based on entity characteristics), the Data
Model contains natural relationships among the entities. For example, in the Data
Model taxonomy, the Student entity is not close to the Class entity, but the Data
Model stores and reflects the relationships between them. The figure below shows
examples of the types of relations contained in the Data Model.
The relationship descriptors include verbs or short verb phrases that connect the
subject with the object. For example, student (subject) receives services from (relation)
teacher (object). This information within the Data Model allows for intelligent
searching and for creation of subparts of a model.
examples of possible relationship descriptors include:
- Participates in
Types of Relationships in the Education Data Model.
The entities, classes and attributes in the Data Model are organized into a taxonomy.
As illustrated below, entities (marked with E) are organized into classes and subclasses
(marked with C). Each entity has its own set of attributes (marked with A). Entities
are grouped together based upon common characteristics.
Taxonomies arrange items into categories based on like characteristics. For example,
lesson plan and unit plan are both types of academic plans in the Data Model, but
lesson plan and unit plan differ based upon the scope and purpose of the plan. The
“is a type of” organization scheme ensures, with few exceptions, that each entity
has one, and only one, place in the arrangement.
For example, in the Data Model, a portfolio is a type of formative assessment is
a type of assessment is a type of instruction artifact.
Just like in the Linnaean taxonomy of living things, a homo sapien is a type of
hominidae is a type of primate is a type of mammal is a type of chordate is a type
There are exceptions and hard-to-classify cases, similar to the duck-billed platypus
in the taxonomy of living things, which, as a mammal that lays eggs, defies a clean
classification. The Data Model taxonomy is similar in form and function to other
well-known taxonomies, such as the Linnaean taxonomy of living things discussed
above or historically used classification systems such as the Dewey Decimal system.
As one becomes familiar with the structure of the taxonomy, locating a particular
entity becomes easy. In addition, the provided tools for using the Data Model have
search features that provide convenient means for locating items in the taxonomy.
Taxonomy of Classes, Entities, and Attributes
7. Concept Map
The Concept Map describes the structure of the Education Data Model. It represents
a logical and finite set of relationships among classes, sub-classes, and entities,
thereby striving to depict the entire domain of education information. It adds multiple
simultaneous relationships among the entities to the taxonomy. The relationships
among entities are designed to be mutually exclusive but may sometimes overlap in
meaning or usage. To feature the relationships among the entities presented previously
in figure B, figure G turns the taxonomy inward.
Data Model Top-Level Classes
In the Data Model the content is arranged in a tree-type structure. There are ten
top-level classes (or branches) of the tree. On the Data Model screen, the list
on the left allows the user to “drill down” into the subclasses that are below each
Association - Functional associations among individuals, organizations, events,
Education Leadership Artifact - Artifacts are related to the leadership of
teaching and learning processes.
Event - The Event entities represent any event within the education organization.
Information Exchange - The Information Exchange entities represent information being
Instruction Artifact - These entities represent any piece of information related
to a student’s learning or the general learning process.
Operations Artifact - These entities relate to the administrative or operational
side of the organization.
Organization - These entities represent the grouping of resources and people in
order to reach a particular goal.
Person - Individuals within the education setting.
Place - These entities represent the locality or area within the education environment.
Program - A plan of activities and procedures to accomplish a set of objectives.
x_Extensions - This class is not a regular part of the Data Model. It is a category
that contains extensions to the Data Model. For example, the category could hold
Education Data Exchange Network (EDEN) input file definitions or fact table definitions
for a data warehouse. This category allows concepts that are not allowed in the
Data Model, such as aggregate statistics or report definitions, to be linked to
entities and relationships in the Data Model.
in the Data Model
Rather than present long lists of entity items, entities are presented in a hierarchy
or taxonomy. Each entity is classified according to one or more levels of class.
The classes serve to group entities based upon like characteristics or function.
This is similar to the Library of Congress or the Dewey Decimal system in which
books are organized by subject. If you know a little about the characteristics of
the book you are looking for, even if you do not know its name, you have a good
chance of easily finding the book.
However, grouping based upon similar characteristics do not always place things
that have a strong relation to each other in close proximity. For example a book
about Abraham Lincoln’s presidential policy successes and failures might be in a
political science section while a book about the civil war would be in the history
section even though they are very closely related when one wants to know more about
the context within which Lincoln made his most important decisions.
Similarly, an education entity such as lesson, or lesson plan might not be located
near a teacher in the taxonomy. Though the design of lesson plans and the delivery
by teachers of lessons to students are important process scenarios that show a strong
relation among the lesson, lesson plan, teacher, and student entities, this relationship
is not reflected in the taxonomy. The Data Model does have a mechanism that allows
important relationships among entities to be contained within the Data Model. The
Relationships section of each Entity page shows the important relationships of each
entity to other entities.