Description:
The content model for attribute is a CHOICE between "references" and all of the elements that let you describe the attribute (e.g., attributeName,attributeDefinition,precision)The attribute element allows a user to document the characteristics that describe a 'field' or 'variable' in a data entity (e.g. dataTable). Complete attribute descriptions are perhaps the most aspect to making data understandable to others. An attribute element describes to a single attribute. An attribute element can contain a reference to an attribute defined elsewhere. Using a reference means that the referenced attribute is identical, not just in name but identical in its complete description. For example, if attribute "measurement1" in dataTable "survey1" has a precision of 0.1 and you are documenting dataTable survey2 which has an attribute called "measurement1" but the survey2's measurement1 has a precision of 0.001 then these are different attributes.
Example:
Because the attribute element is a container for other elements, look at the contents of its sub-elements for examples of what to enter.

Description:
This element specifies name of the attribute (field) in the dataset. This information is typically found as the column header (first row) for the field/variable in a spreadsheet. It is usually terse, without spaces, and can be used to "name" a column in a table definition statement in a RDBMS.
Example:
spden

Description:
A brief label used to describe the attribute. This is often needed because attribute names are usually very terse: often shortened to 8 characters or less to fit the requirements of analysis or other software systems. A label is provided as a concise but more descriptive representation of the attribute's name.
Example:
"Species Density" is a label for attribute with name "spden"

Description:
This element gives a precise definition of attribute in the data entity (dataTable, spatialRaster, spatialVector, storedProcedure, view or otherEntity) being documented. It explains the contents of the attribute fully and possibly provides pointers to the methods used to generate the attribute data.
Example:
"spden" is the number of individuals of all macroinvertebrate species found in the plot

Description:
This field identifies the unit of measurement for this attribute. It is a choice of either a standard SI unit, or a custom unit. If it is a custom unit, the definition of the unit must be provided in the document using the STMML syntax, and the name provided in the customUnit element must reference the id of its associated STMML definition precisely. For further information on STMML (http://www.xml-cml.org/stmml/) or see stmml.xsd which is included with the EML 2.0 distribution for details.
Example:

Description:
The standardUnit element is the name of the standard unit used in making this measurement. The name must be one of the values defined in the unitDictionary. These are the major SI units and some commonly used units outside of SI. See the STMML definition of each unit that ships with EML for more information.
Example:
meter

Description:
An entry in the customUnit element is the name of a custom unit that is not part of the standard list provided with EML. The unit must correspond to an id in the document where that definition is provided using the STMML syntax. The customUnit definition will most likely be in the additionalMetadata section.
Example:
emergy

Description:
This element describes the storage type, commonly referred to as datatype, for data in a RDBMS (or otherdata management system) field. As many systems do not provide for fine-grained restrictions on types, this type will often be a superset of the allowed domain defined in attributeDomain. Values for this field are by default drawn from the XML Schema Datatypes standard values, such as: integer, double, string, etc. If the XML Schema datatypes are not used, the type system from which the values are derived should be listed in the 'typeSystem' attribute described below. This field represents a 'hint' to processing systems as to how the attribute might be represented in a system or language, but is distinct from the actual expression of the domain of the attribute. The field is repeatable so that the storageType can be indicated for multiple type systems (e.g., Oracle data types and Java data types).
Example:
integer

Description:
The measurementScale element is the scale of the measured attribute. This provides information about the scale in which the data was collected. The allowed values are 'ratio', 'ordinal', 'nominal' and 'interval'.
Example:
nominal

Description:
The codeDefinition element describes any code associated with the attribute. These codes can be defined here in the metadata as a list with definitions (preferred), can be referenced by pointing to an external citation or URL where the codes are defined, or can be referenced by pointing at an entity that contains the code value and code definition as two attributes. Note that because this element is optional, if it is omitted, the value of the attribute's domain is taken to be the regular expression (.*) (any text).
Example:
The format will typically be : "code" has "definition", e.g. "1" = "high", "2" = "medium", "3" = "low"

Description:
The codeList element contains a list of codes and their definitions.

Description:
The code element specifies a code associated with the attribute.
Example:
"1" would be the code for "high" (where high is the description of the code)

Description:
The definition describes the code associated with the attribute.
Example:
"high" would be the definition for a code of "1"

Description:
The source element is the name of the source from which this code and its associated definition are drawn. This is commonly used for identifying standard coding systems, like the FIPS standard for postal abbreviations for states in the US. In other cases, the coding may be the researcher's customized way of recording and classifying their data, and no external "source" would exist.
Example:
ISO country codes

Description:
The externalCodeSet element is a reference to an externally defined set of codes used in this attribute. This can either be a citation (using the eml-citation module) or a URL.

Description:
The codesetName element is the name of an externally defined code set.
Example:
FIPS State Abbreviation Codes

Description:
The citation element is a citation for the code set reference

Description:
The codesetURL element is a URL for the code set reference.

Description:
The entityCodeList is a list of codes and their definitions in a data entity.

Description:
The entityReference element is a reference to the id of the entity in which the code list has been defined. This entity must have been defined elsewhere in the metadata and have an id that matches the value of this element.

Description:
The valueAttributeReference element is a reference to the id of the attribute that contains the list of codes. This attribute must have been defined elsewhere in the metadata and have an id that matches the value of this element.

Description:
The definitionAttributeReference element is a reference to the id of the attribute that contains the definition of codes. This attribute must have been defined elsewhere in the metadata and have an id that matches the value of this element.

Description:
The textDomain element describes a free text domain for the attribute. By default, if a pattern is missing or empty, then any text is allowed. If a pattern is present, then it is interpreted as a regular expression constraining the allowable character sequences for the attribute.
Example:
Typically, a textdomain will have an empty pattern or one that constrains allowable values. For example, '[0-9]{3}-[0-9]{3}-[0-9]{4}' allows for only numeric digits in the pattern of a US phone number.

Description:
The element definition provides the text domain definition, that is, what kinds of text expressions are allowed for this attribute. If there is a pattern supplied, the definition element expresses the meaning of the pattern, For example, a particular pattern may be meant to represent phone numbers in the US phone system format. A definition element may also be used to extend an enumerated domain.
Example:
US telephone numbers in the format "(999) 888-7777"

Description:
The pattern element specifies a regular expression pattern that constrains the set of allowable values for the attribute. This is commonly used to define template patterns for data such as phone numbers where the attribute is text but the values are not drawn from an enumeration. If the pattern field is empty or missing, it defaults to '.*', which matches any string, including the empty string. Repeated pattern elements are combined using logical OR. The regular expression syntax is the same as that used in the XML Schema Datatypes Recommendation from the W3C.
Example:
'[0-9a-zA-Z]' matches simple alphanumeric strings and '(\d\d\d) \d\d\d-\d\d\d\d' represents telephone strings in the US of the form '(704) 876-1734'

Description:
The source element is the name of the source from which this text domain and its associated definition are drawn. This is commonly used for identifying standard coding systems, like the FIPS standard for postal abbreviations for states in the US. In other cases, the coding may be a researcher's custom way of recording and classifying their data, and no external "source" would exist.
Example:
ISO country codes

Description:
The numericDomain element specifies the minimum and maximum values of a numeric attribute. These are theoretical or permitted values (ie. prescriptive), and not necessarily the actual minimum and maximum occurring in a given data set (descriptive).
Example:

Description:
The minimum element specifies the minimum value range of numeric attribute.
Example:

Description:
The maximum element specifies the maximum value range of a numeric attribute.
Example:

Description:
This element is to specify missing value in the data of the field.
Example:

Description:
The code element is the missing value code itself. Each missing value code should be entered in a separate element instance. The value entered is what is placed into a data grid if the value is missing for some reason.
Example:
-9999

Description:
The codeExplanation element is an explanation of the meaning of the missing value code that was used, that is, the reason that there is a missing value.
Example:
Sensor down time.

Description:
The precision element represents the precision of the measurement, in the same unit as the measurement. For example, for an attribute with unit "meter", a precision of "0.1" would be interpreted as precise to the nearest 1/10th of a meter.
Example:
0.1

Description:
The accuracy element represents the accuracy of the attribute. This information should describe any accuracy information that is known about the collection of this data attribute. The content model of this metadata is taken directly from FGDC FGDC-STD-001-1998 section 2 with the exception of processContact, sourceCitation, and timePeriodInformation which either user XMLSchema types or use predefined EML types for these purposes.
Example:

Description:
The attributeAccuracyReport element is an explanation of the accuracy of the observation recorded in this attribute. It will often include a description of the tests used to determine the accuracy of the observation. These reports are generally prepared for remote sensing or other measurement devices.
Example:

Description:
The quantitativeAttributeAccuracyAssessment element is composed of two parts, a value that represents the accuracy of the recorded observation an explanation of the tests used to determine the accuracy.
Example:

Description:
The attributeAccuracyValue element is an estimate of the accuracy of the identification of the entities and assignments of attribute values in the data set. ??
Example:

Description:
The attributeAccuracyExplanation element is the identification of the test that yielded the Attribute Accuracy Value.
Example:

Type: xs:string

Use: optional

Type: xs:string

Use: optional

Description:
The typeSystem element is the system used to define the storage types. This should be an identifier of a well known and published typing system. The default and recommended system is the XML Schema data type system. For details go to http://www.w3.org. If another system is used (such as Java or C++ types), typeSystem should be be changed to match the system.
Example:
http://www.w3.org/2001/XMLSchema-datatypes

Type: xs:string

Use: optional

Type: xs:string

Use: optional

Type: res:ScopeType

Use: optional

Description:
This complexType defines the structure of the attributeList element. The content model is a choice between one or more attribute elements, and references. References link attribute elements defined elsewhere.
Example:

Description:
Describes the structure for the container of attribute descriptors for a specific attribute in a dataset.
Example:

Derived from: xs:string (by xs:restriction)

Allowed values:

• ratio
• nominal
• ordinal
• interval

Derived from: xs:string (by xs:restriction)

Allowed values:

• yes
• no

Derived from: xs:string (by xs:restriction)

Allowed values:

• second
• meter
• kilogram
• kelvin
• coulomb
• ampere
• mole
• candela
• number
• nanogram
• microgram
• milligram
• centigram
• decigram
• gram
• dekagram
• hectogram
• megagram
• Celsius
• nanometer
• micrometer
• micron
• millimeter
• centimeter
• decimeter
• dekameter
• hectometer
• kilometer
• megameter
• angstrom
• nanosecond
• microsecond
• millisecond
• centisecond
• decisecond
• dekasecond
• hectosecond
• kilosecond
• megasecond
• minute
• hour
• microliter
• milliliter
• liter
• gallon
• quart
• radiam
• degree
• megahertz
• kilohertz
• hertz
• millihertz
• newtom
• joule
• calorie
• british thermal unit
• foot pound
• lumen
• lux
• becquerel
• gray
• sievert
• katal
• henry
• megawatt
• kilowatt
• watt
• milliwatt
• megavolt
• kilovolt
• volt
• millivolt
• farad
• ohm
• ohmMeters
• siemens
• weber
• tesla
• pascal
• megapascal
• kilopascal
• atmosphere
• bar
• millibar
• poundsPerSquareInch
• milliGramsPerMilliLiter
• gramsPerLiter
• kilogramsPerCubicMeter
• milligramsPerCubicMeter
• microgramsPerLiter
• milligramsPerLiter
• gramsPerCubitCentimeter
• gramsPerMilliliter
• gramsPerLiterPerDay
• litersPerSecond
• milligramsPerSquareMeter
• are
• hectare
• kilogramsPerHectare
• squareKilometers
• squareMillimeters
• squareCentimeters
• tonne
• tonnePerHectare
• bushel
• acre
• bushelsPerAcre
• litersPerHectare
• squareMeterPerKilogram
• squareMeter
• cubitMeter
• cubicMeter
• metersPerSecond
• metersPerSecondSquared
• waveNumber
• cubicMeterPerKilogram
• amperePerSquareMeter
• amperePerMeter
• molePerCubicMeter
• candelaPerSquareMeter
• molarity
• molality
• metersPerDay
• feetPerDay
• feetPerSecond
• feetPerHour
• yardsPerSecond
• milesPerHour
• milesPerSecond
• milesPerMinute
• cubicFeetPerSecond
• kilogramPerCubicMeter
• metersSquaredPerDay
• feetSquaredPerDay
• centimetersPerSecond
• millimetersPerSecond
• gramsPerCentimeterSquaredPerSecond
• gramsPerMeterSquaredPerYear
• kilogramsPerHectarePerYear
• kilogramsPerMeterSquaredPerYear
• centimeterPerYear
• molesPerGram
• millimolesPerGram
• amountOfSubstanceWeightFlux
• tonnesPerYear
• gramsPerYear
• numberPerMeterSquared
• numberPerKilometerSquared
• numberPerMeterCubed
• inch
• foot
• fathom
• nauticalMile
• yard
• mile
• pint
• pound
• ton
• squareFoot
• squareYard
• squareMile
• cubicInch
• fahrenheit

Description:
The unitDictionary element enumerates the standard set of units that are included with the EML distribution, mailnly from the SI standard. These unit names can be used in the standardUnit filed to describe an attribute's units. The units are defined in the STMML language in a document that is shipped with each release of EML.