Unit¶
Generalization is AnnotatedIdentifiable.
Superclass hierarchy
Definition¶
Individual object of interest for some statistical activity, such as data collection
Examples¶
Here are 3 examples - 1. Individual US person (i.e., Arofan Gregory, Dan Gillman, Barack Obama, etc.) 2. Individual US computer companies (i.e., Microsoft, Apple, IBM, etc.) 3. Individual US universities (i.e., Johns Hopkins, University of Maryland, Yale, etc.) [GSIM 1.1].
Explanatory notes¶
In a traditional data table each column might represent some variable (measurement). Each row would represent the entity (Unit) to which those variables relate. Height measurements might be made on persons (UnitType) of primary school age (Universe) at Pinckney Elementary School on September 1, 2005 (Population). The height for Mary Roe (Unit) might be 139 cm.
The Unit is not invariably tied to some value. A median income might be calculated for a block in the U.S. but then used as an attribute of a person residing on that block. For the initial measurement the Unit was the block. In the reuse the unit would be that specific person to which the value was applied.
In a big data table each row represents a unit/variable double. Together a unit identifier and a variable identifier define the key. And for each key there is just one value – the measure of the unit on the variable.
A big data table is sometimes referred to as a column-oriented data store whereas a traditional database is sometimes referred to as a row-oriented data store. The unit plays an identifier role in both types of data stores.
Subclasses¶
Properties¶
Name |
Description |
Data Type |
Multi- plicity |
---|---|---|---|
definition
from Unit
|
Natural language statement conveying the meaning of a concept, differentiating it from other concepts. Supports the use of multiple languages and structured text. |
0..1 |
|
displayLabel
from Unit
|
A structured display label providing a fully human readable display for the identification of the object. Supports the use of multiple languages and structured text. |
0..* |
|
name
from Unit
|
A linguistic signifier. Human understandable name (word, phrase, or mnemonic) that reflects the ISO/IEC 11179-5 naming principles. If more than one name is provided provide a context to differentiate usage. |
0..* |
Inherited Properties¶
Name |
Description |
Data Type |
Multi- plicity |
---|---|---|---|
agency
from Identifiable
|
Agency expressed as filed with the DDI Agency ID registry [registry.ddialliance.org] with optional additional sub-agency extensions. |
:ref:`` |
1..1 |
id
from Identifiable
|
ID conforming to the allowed structure of the DDI Identifier and must be unique within the Agency. |
:ref:`` |
1..1 |
isPersistent
from Identifiable
|
Default value is false indicating that the content of the current version may change (may be in development mode). Set to true when the content of this version will no longer change. |
:ref:`` |
1..1 |
isUniversallyUnique
from Identifiable
|
Default value is false. If the id of the object was created as a Universally Unique ID (UUID) set to true. |
:ref:`` |
1..1 |
localId
from Identifiable
|
Locally used identifier unique with a specified context, such as a variable name within a dataset. |
0..* |
|
version
from Identifiable
|
Version number of the object. |
:ref:`` |
1..1 |
versionDate
from Identifiable
|
Date and time the object was changed expressed in standard ISO formats. |
0..1 |
|
versionRationale
from Identifiable
|
Reason for making a new version of the object. |
0..1 |
|
versionResponsibility
from Identifiable
|
Contributor who has the ownership and responsibility for the current version. |
:ref:`` |
0..1 |
Diagram¶
TBD