DDI4 Schema

Definition

A basic structure for declaring the name of an Agent inline, reference to an Agent, and role specification. This object is used primarily within Annotation.

DDI 3.2 mapping

r:ContributorType

Definition

Provides annotation information on the object to support citation and crediting of the creator(s) of the object.

DDI 3.2 mapping

r:CitationType

Definition

A generic date type for use in Annotation which provides the standard date structure plus a property to define the date type (Publication date, Accepted date, Copyrighted date, Submitted date, etc.).

Synonyms

Equivalent of http://purl.org/dc/elements/1.1/date where the type of date may identify the Dublin Core refinement term.

Definition

Binds two parameters together to direct flow of data through a process

Examples

From the output of an InstanceQuestion to the input of a ComputationAction

Explanatory notes

Binding is used to define the flow of data into, out of, and within a process. It is separate from the flow of a process. When used in the workflow of a data capture process most data may go from a capture to an instance variable, but when needed as a check sum in a loop, a recoding process, or conditional content for DynamicText, Binding provides the means for explicitly directing the movement of data from one point to another in the process.

Definition

A BusinessProcess precondition or post condition which describes the condition which must be met to begin (pre) or exit (post) a process. It may use a specified LogicalRecord. The Logical Record has SQL that describes it, rejectionCriteria against which its adequacy may be tested and an optional annotation that describes its provenance.

Definition

Contains information on the command used for processing data. Contains a description of the command which should clarify for the user the purpose and process of the command, an in-line provision of the command itself, and a reference to an external version of the command such as a coding script.

DDI 3.2 mapping

r:CommandCodeType

Definition

Text which has a changeable value depending on a stated condition, response to earlier questions, or as input from a set of metrics (pre-supplied data). The command code indicates the condition and/or calculation used to determine the content of the text.

DDI 3.2 mapping

d:ConditionalTextType

Definition

Contact information for the individual or organization including location specification, address, web site, phone numbers, and other means of communication access. Address, location, telephone, and other means of communication can be repeated to express multiple means of a single type or change over time. Each major piece of contact information contains the element EffectiveDates in order to date stamp the period for which the information is valid.

DDI 3.2 mapping

a:ContactInformationType

Definition

Identifies the difference between the date applied to the data as a whole and this specific item such as previous year's income or residence 5 years ago. A value of true for the attribute isNegativeOffset indicates that the offset is the specified number of declared units prior to the date of the data as a whole and false indicates information regarding a future state.

DDI 3.2 mapping

r:ContentDateOffsetType

Definition

Describes the commonalities and differences between two members using a textual description of both commonalities and differences plus an optional coding of the type of commonality.

DDI 3.2 mapping

cm:CorrespondenceType

Definition

Provides the structure of a single Date expressed in an ISO date structure along with equivalent expression in any number of non-ISO formats. While it supports the use of the ISO time interval structure this should only be used when the exact date is unclear (i.e. occurring at some point in time between the two specified dates) or in specified applications. Ranges with specified start and end dates should use the DateRange as a datatype. Commonly uses property names include: eventDate, issueDate, and releaseDate.

Explanatory notes

Date allows one of a set of date-time (YYYY-MM-DDThh:mm:ss), date (YYYY-MM-DD), year-month (YYYY-MM), year (YYYY), time (hh:mm:ss) and duration (PnYnMnDnHnMnS), or time interval (YYYY-MM-DDThh:mm:ss/YYYY-MM-DDThh:mm:ss, YYYY-MM-DDThh:mm:ss/PnYnMnDnHnMnS, PnYnMnDnHnMnS/ YYYY-MM-DDThh:mm:ss) which is formatted according to ISO 8601 and backed supported by regular expressions in the BaseDateType. Time Zone designation and negative/positive prefixes are allowed as are dates before and after 0000 through 9999.

DDI 3.2 mapping

r:DateType

Definition

Expresses a date/time range using a start date and end date (both with the structure of Date and supporting the use of ISO and non-ISO date structures). Use in all locations where a range of dates is required, i.e. validFor, embargoPeriod, collectionPeriod, etc.

DDI 3.2 mapping

r:DateType

Definition

Describes a bounding value for a number range expressed as an xs:double.

DDI 3.2 mapping

r:DoubleNumberRangeValueType

Definition

Structure supporting the use of dynamic text, where portions of the textual content change depending on external information (pre-loaded data, response to an earlier query, environmental situations, etc.).

Examples

Purpose: Provide customized number of hours within a question text Input is the OutputParameter from Question "What time did you take this medication?" Literal Text: "During the past " [0] Conditional Text / Command: PastTime=Input; Round PastTime to nearest hour; Round CurrentTime to nearest hour; CurrentTime - PastTime = HOURS; content=HOURS [1] Literal Text: " hours which of the following symptoms have you experienced?" [2]

Result in question text for a PastTime= 06:10; CurrentTime=14:54 "During the past 9 hours which of the following symptoms have you experienced?"

DDI 3.2 mapping

d:DynamicTextType

Definition

Abstract type existing as the head of a substitution group. May be replaced by any valid member of the substitution group TextContent. Provides the common property of purpose to all members using TextContent as an extension base. Provides a Purpose for the content and ordering information within the Dynamic Text. May be a LiteralText or ConditionalText.

DDI 3.2 mapping

d:TextContentType

Definition

Allows for unstructured content which may be an entry from an externally maintained controlled vocabulary.If the content is from a controlled vocabulary provide the code value of the entry, as well as a reference to the controlled vocabulary from which the value is taken. Provide as many of the identifying attributes as needed to adequately identify the controlled vocabulary. Note that DDI has published a number of controlled vocabularies applicable to several locations using the ExternalControlledVocabularyEntry structure. If the code portion of the controlled vocabulary entry is language specific (i.e. a list of keywords or subject headings) use language to specify that language. In most cases the code portion of an entry is not language specific although the description and usage may be managed in one or more languages. Use of shared controlled vocabularies helps support interoperability and machine actionability.

DDI 3.2 mapping

r:CodeValueType

Definition

The static portion of the text expressed as a StructuredString with the ability to preserve whitespace if critical to the understanding of the content.

DDI 3.2 mapping

d:TextType

Definition

A reference to an image, with a description of its properties and type.

DDI 3.2 mapping

r:ImageType

Definition

Allows for the identification of the InstanceVariable specifically as a member and optionally provides an index for the member within an ordered array.

Explanatory notes

Note if multiple types of Variables may be included in a collection use VariableIndicator.

Definition

An identifier whose scope of uniqueness is broader than the local archive. Common forms of an international identifier are ISBN, ISSN, DOI or similar designator. Provides both the value of the identifier and the agency who manages it.

Explanatory notes

For use in Annotation or other citation format.

DDI 3.2 mapping

r:InternationalIdentifierType

Definition

Packaging structure for multiple language versions of the same string content. Where an element of this type is repeatable, the expectation is that each repetition contains different content, each of which can be expressed in multiple languages. The language designation goes on the individual String.

DDI 3.2 mapping

r:InternationalStringType

Definition

Packaging structure for multiple language versions of the same string content, for objects that allow for internal formatting using XHTML tags. Where an element of this type is repeatable, the expectation is that each repetition contains different content, each of which can be expressed in multiple languages.

DDI 3.2 mapping

r:StructuredStringType

Definition

A structured display label. Label provides display content of a fully human readable display for the identification of the object.

DDI 3.2 mapping

r:LabelType

Definition

Allows for non-formatted language specific strings that may be translations from other languages, or that may be translatable into other languages. Only one string per language/scope type is allowed. LanguageSpecificString contains the following attributes, xmlang to designate the language, isTranslated with a default value of false to designate if an object is a translation of another language, isTranslatable with a default value of true to designate if the content can be translated, translationSourceLanguage to indicate the source languages used in creating this translation, translationDate, and scope which can be used to define intended audience or use such as internal, external, etc.

DDI 3.2 mapping

r:StringType

Definition

Supports the optional use of formatting tags expressed with escape characters within the string structure. Language of the string is defined by the attribute language. Scope of the string is defined by scope. Language and Scope are used to filter selection and use of content based on unique combinations of these two properties. The content can be identified as translated (isTranslated), subject to translation (isTranslatable), the result of translation from one or more languages (translationSourceLanguages), carry an indication whether or not it should be treated as plain text (isPlain), identification of the structure used (structureUsed) which is an internal enumeration, and the ability to identify a structure not available in the enumeration by declaring structureUsed="Other" and specifying the other structure (otherDefined).

Examples

The content:

a bit of text

with some specialties highlighted

Would be entered as:

with some specialties highlighted

DDI 3.2 mapping

r:ContentType

Definition

Literal (static) text to be used in an instrument. The value is a LanguageSpecificStruccturedString with the addition of an attribute allowing for the specification that white space is to be preserved.

Examples

The text string " Comment vous appelez-vous?" with the leading spaces included, described as being in French.

DDI 3.2 mapping

d:LiteralTextType

Definition

Name of the location using the DDI Name structure and the ability to add an effective date.

DDI 3.2 mapping

a:LocationNameType

Definition

Describes the correspondence between concepts in a correspondence table related to one or more Statistical Classifications.

Explanatory notes

A Map is the pairing of similar Concepts. Each Concept in the Map belongs to a different Collection. The collection of maps for all the Concepts in corresponding Collections is a Correspondence Table.

A simple example might map the following 2 martial status category sets: MS1 - single married widowed divorced

MS2 - single married

So, a correspondence table between these 2 category sets might look like this: MS1 MS2 single single widowed " divorced " married married

GSIM mapping

Map

Definition

Describes a bounding value for a number range expressed as an xs:demical.

DDI 3.2 mapping

r:NumberRangeValueType

Definition

A standard means of expressing a Name for a class object. A linguistic signifier. Human understandable name (word, phrase, or mnemonic) that reflects the ISO/IEC 11179-5 naming principles.

Explanatory notes

USE in Model: In general the property name should be "name" as it is the name of the class object which contains it. Use a specific name (i.e. xxxName) only when naming something other than the class object which contains it.

DDI 3.2 mapping

r:NameType

Definition

A tightly bound pair of items from an external controlled vocabulary. The extent property describes the extent to which the parent term applies for the specific case.

Examples

When used to assign a role to an actor within a specific activity this term would express the degree of contribution. Contributor with Role=Editor and extent=Lead.

Alternatively. the term might be a controlled vocabulary from a list of controlled vocabularies, e.g. the Generic Longitudinal Business Process Model (GLBPM) in a list that could include other business process model frameworks. In this context the extent becomes the name of a business process model task, e.g. "integrate data" from the GLBPM.

Definition

A closed plane figure bounded by three or more line segments, representing a geographic area. Contains either the URI of the file containing the polygon, a specific link code for the shape within the file, and a file format, or a minimum of 4 points to describe the polygon in-line. Note that the first and last point must be identical in order to close the polygon. A triangle has 4 points.

DDI 3.2 mapping

r:PolygonType

Definition

Describes a bounding value of a string.

DDI 3.2 mapping

r:RangeValueType

Definition

Lists the value and format type for the coordinate value. Note that this is a single value (X coordinate or Y coordinate) rather than a coordinate pair.

DDI 3.2 mapping

r:SpatialCoordinateType

Definition

A geographic point consisting of an X and Y coordinate. Each coordinate value is expressed separately providing its value and format.

DDI 3.2 mapping

r:PointType

Definition

Used to specify a relationship between one spatial object and another. Includes definition of the spatial object types being related, the spatial relation specification, and the event date.

Definition

The value of the statistic expressed as an xs:decimal and/or xs:double. Indicates whether it is weighted value and the computation base.

DDI 3.2 mapping

pi:StatisticType

Definition

TypedString combines a typeOfContent with a content defined as a simple string. May be used wherever a simple string needs to support a type definition to clarify its content

Examples

content is a regular expression and typeOfContent is used to define the syntax used.

Explanatory notes

This is a generic type + string where property name and documentation should be used to define any specification for the content. If international structured string content is required use TypedStructuredString

Definition

The Value expressed as an xs:string with the ability to preserve whitespace if critical to the understanding of the content.

DDI 3.2 mapping

r:ValueType

Definition

A Concept whose role is to define and measure a characteristic.

Examples

Self-identified as "Male". "Extremely Satisfied" as a response category.

Explanatory notes

The Category is a Concept. It can have multiple name and display label properties as well as a definition and some descriptive text. As a "Signified" class there can be one or more "Sign" classes (e.g. a Code) that denotes it with some representation. The relationship is from the Code to the Category.

DDI 3.2 mapping

l:CategoryType

Definition

Unit of thought differentiated by characteristics [GSIM 1.1]

Examples

Poverty, Income, Household relationship, Family, Gender, Business Establishment, Satisfaction, etc.

Explanatory notes

Many DDI4 classes are subtypes of the Concept class including Category, Universe, UnitType, ConceptualVariable. This class realizes the pattern class Signified and as such a Concept can be denoted by a Sign.

DDI 3.2 mapping

c:ConceptType

GSIM mapping

Concept

Definition

A set of Concepts structured by the relations among them. [GSIM 1.1]

Examples

1) Concept of Sex: Male, Female, Other 2) Concept of Household Relationship: Household Head, Spouse of Household Head, Child of Household Head, Unrelated Household Member, etc.

Explanatory notes

Note that this structure can be used to structure Concept, Classification, Universe, Population, Unit Type and any other class that extends from Concept.

DDI 3.2 mapping

c:ConceptSchemeType

GSIM mapping

Concept System

Definition

Relationship between 2 or more ConceptSystems described through mapping similarity relationships between their member Concepts.

Examples

Correspondence between the concepts used to define the populations in the censuses of two countries with similarity mapping of Concepts "Resident Population", "Labor Force", "Housing Unit", etc.

Explanatory notes

Describes correspondence with one or more Maps which identify a source and target concept and defines their commonality and difference using descriptive text and controlled vocabularies.

Definition

Set of Concepts, both sentinel and substantive, that can be described by either enumeration or by an expression.

Examples

Substantive: Housing Unit Tenure - Owned, Rented, Vacant; Sentinel: Non-response - Refused, Don't Know, Not Applicable

Explanatory notes

Intent of a Conceptual Domain is defining a set of concepts used to measure a broader concept. For effective use they should be discrete (non-overlapping) and provide exhaustive coverage of the broader concept.

Definition

The use of a Concept as a characteristic of a UnitType intended to be measured

Examples

1. Sex of person
2. Number of employees
3. Value of endowment

Explanatory notes

Note that DDI varies from GSIM in the use of a UnitType rather than a Universe. "The use of a Concept as a characteristic of a Universe intended to be measured" [GSIM 1.1]

DDI 3.2 mapping

c:ConceptualVariableType

GSIM mapping

Variable

Definition

The use of a Represented Variable within a Data Set. The InstanceVariable describes actual instances of data that have been collected.

Examples

1) Gender: Dan Gillman has gender <m, male>, Arofan Gregory has gender<m, male>, etc. 2) Number of employees: Microsoft has 90,000 employees; IBM has 433,000 employees, etc. 3) Endowment: Johns Hopkins has endowment of <3, $1,000,000 and above>, Yale has endowment of <3, $1,000,000 and above>, etc.

Two InstanceVariables of a person's height reference the same RepresentedVariable. This indicates that they are intended to: be measured with the same unit of measurement, have the same intended data type, have the same SubstantativeValueDomain, use a SentinelValueDomain drawn from the same set of SentinelValueDomains, have the same sentinel (missing value) concepts, and draw their Population from the same Universe. In other words, the two InstanceVariables should be comparable.

Explanatory notes

The InstanceVariable class inherits all of the properties and relationships of the RepresentedVariable (RV) class and, in turn, the ConceptualVariable (CV) class. This means that an InstanceVariable can be completely populated without the need to create an associated RepresentedVariable or ConceptualVariable. If, however, a user wishes to indicate that a particular InstanceVariable is patterned after a particular RepresentedVariable or a particular ConceptualVariable that may be indicated by including a relationship to the RV and or CV. Including these references is an important method of indicating that multiple InstanceVariables have the same representation, measure the same concept, and are drawn from the same Universe. If two InstanceVariables of a person's height reference the same RepresentedVariable. This indicates that they are intended to: be measured with the same unit of measurement, have the same intended data type, have the same SubstantativeValueDomain, use a SentinelValueDomain drawn from the same set of SentinelValueDomains, have the same sentinel (missing value) concepts, and draw their Population from the same Universe. In other words, the two InstanceVariables should be comparable.

GSIM mapping

Instance Variable

Definition

Set of specific units (people, entities, objects, events) with specification of time and geography.

Examples

1. Canadian adult persons residing in Canada on 13 November 1956
2. US computer companies at the end of 2012
3. Universities in Denmark 1 January 2011.

Explanatory notes

Population is the most specific in the conceptually narrowing hierarchy of UnitType, Universe and Population. Several Populations having differing time and or geography may specialize the same Universe.

GSIM mapping

Population

Definition

A combination of a characteristic of a universe to be measured and how that measure will be represented.

Examples

The pair (Number of Employees, Integer), where "Number of Employees" is the characteristic of the population (Variable) and "Integer" is how that measure will be represented (Value Domain).

Explanatory notes

Extends from ConceptualVariable and can contain all descriptive fields without creating a ConceptualVariable. By referencing a ConceptualVariable it can indicate a common relationship with RepresentedVariables expressing the same characteristic of a universe measured in another way, such as Age of Persons in hours rather than years. RepresentedVariable constrains the coverage of the UnitType to a specific Universe. In the above case the Universe with the measurement of Age in hours may be constrained to Persons under 5 days (120 hours old). RepresentedVariable can define sentinel values for multiple storage systems which have the same conceptual domain but specialized value domains.

DDI 3.2 mapping

l:RepresentedVariableType

Definition

Description or list of possible sentinel concepts , e.g. missing values.

Examples

Refused, Don't know, Lost in processing

Synonyms

missing categories

Definition

Set of valid Concepts. The Concepts can be described by either enumeration or by an expression.

Examples

An enumeration of concepts for a categorical variable like "male" and "female" for gender.

Explanatory notes

A ConceptualVariable links a UnitType to a SubstantiveConceptualDomain. The latter can be an enumeration or description of the values (Signified) that the variable may take on. In the enumerated case these are the categories in a CategorySet that can be values, not the codes that represent the values. An example might be the conceptual domain for a variable representing self-identified gender. An enumeration might include the concept of “male” and the concept of “female”. These, in turn, would be represented in a SubstantiveValueDomain by codes in a CodeList like “m” and “f”, or “0” and “1”. A conceptual domain might be described through a ValueAndConceptDescription’s description property of “a real number greater than 0” or through a more formal logicalExpression of “(all reals x such that x >0) “. Even in the described case, what is being described are conceptual, not the symbols used to represent the values. This may be a subtle distinction, but allows specifying that the same numeric value might be represented by 32 bits or by 64 bits or by an Arabic numeral or a Roman numeral.

GSIM mapping

Conceptual Domain

Definition

The object of interest in a process step related to the collection or use of observational data.

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.

GSIM mapping

Unit

Definition

A Unit Type is a type or class of objects of interest.

Examples

Person, Establishment, Household, State, Country, Dog, Automobile

Explanatory notes

UnitType is the most general in the hierarchy of UnitType, Universe, and Population. It is a description of the basic characteristic for a general set of Units. A Universe is a set of entities defined by a more narrow specification than that of an underlying UnitType. A Population further narrows the specification to a specific time and geography. A Unit Type is used to describe a class or group of Units based on a single characteristic with no specification of time and geography. For example, the Unit Type of “Person” groups together a set of Units based on the characteristic that they are ‘Persons’. It concerns not only Unit Types used in dissemination, but anywhere in the statistical process. E.g. using administrative data might involve the use of a fiscal unit. [GSIM 1.1]

Synonyms

Object Class [ISO11179]

GSIM mapping

Unit Type

Definition

A defined set or class of people, entities, events, or objects, with no specification of time and geography, contextualizing a Unit Type

Examples

1. Canadian adults (not limited to those residing in Canada)
2. Computer companies
3. Universities

Explanatory notes

Universe sits in a hierarchy between UnitType and Population, with UnitType being most general and Population most specific. A Universe is a set of entities defined by a more narrow specification than that of an underlying UnitType. A Population further narrows the specification to a specific time and geography.

If the Universe consists of people, a number of factors may be used in defining membership in the Universe, such as age, sex, race, residence, income, veteran status, criminal convictions, etc. The universe may consist of elements other than persons, such as housing units, court cases, deaths, countries, etc. A universe may be described as "inclusive" or "exclusive".

Not to be confused with Population, which includes the specification of time and geography.

DDI 3.2 mapping

c:UniverseType

GSIM mapping

Population

Definition

High level, descriptive, human informative, algorithm statement used to describe the overall methodology.

Explanatory notes

This would most commonly be used in a Codebook along with a MethodologyOverview and a DesignOverview.The underlying properties of the algorithm or method rather than the specifics of any particular implementation. In short a description of the method in its simplest and most general representation.

Definition

High level, descriptive, human informative, design statement The design may be used to specify how a process will be performed in general. This would most commonly be used in a Codebook along with an AlgorithmOverview and a MethodologyOverview. The design informs a specific or implemented process as to its general parameters. Supports specification of any realization of Goal.

Explanatory notes

Allows for the use of any realized Process. The methodology, design, and algorithm of a specific realized process should be used if available. The use of a generic Process such as a WorkflowProcess containing an Act would be appropriate here. Restriction would be done by inclusion of the appropriate realized process class(es) in a Functional View.

Definition

High level, descriptive, human informative methodology statement used to describe the overall methodology, identify related design, algorithm, and process information. A methodology is normally informed by earlier research and clarifies how earlier research methods were incorporated into the current work.

Examples

The target of the relationship from Study: "hasMethodology"

Explanatory notes

This would most commonly be used in a Codebook along with an AlgorithmOverview and a DesignOverview. Note that Process may be described in more detail than a high level overview. Note that the algorithm may be implemented by multiple processes which are not limited to any specific type of Process. This can be constrained by the inclusion of only specific realizations of Process within a Functional View. Note that this MethodologyOverview can be used as a collective description of specific methodologies used by a Study or other broad set of metadata.

Definition

A specific geographic unit of a defined Unit Type. A geographic unit may change its name, composition, or geographic extent over time. This may be tracked by versioning the content of the geographic unit. Normally a new version of a geographic unit would have a geographic (spatial) overlap with its previous version (a city annexing new area). A geographic unit ends when it is no longer a unit of the same unit type.

Examples

The State of Minnesota from 1858 to date where the Unit Type is a State as defined by the United States Census Bureau. It has a geographic extent and supersedes a portion of the Territory of Minnesota and a portion of the Territory of Wisconsin. Minnesota territory had both a broader geographic extent, different Unit Type, and earlier time period (1849-1858) as did the Territory of Wisconsin.

DDI 3.2 mapping

r:GeographicLocationType

Definition

Describes the classification of specific geographic units into a classification system. As a subtype of Code List it can be used directly for the description of a value domain.

Definition

A structured collection of Unit Types defining a geographic structure. As a subtype of CodeList it may be used directly to describe a value domain.

Examples

Country--State--County

Definition

The information needed for understanding the physical structure of data coming from a file or other source. A StructureDescription also points to the Data Store it physically represents.

Examples

The PhysicalDataProduct is the entry point for information about a file or other source. It includes information about the name of a file, the structure of segments in a file and the layout of segments.

Explanatory notes

Multiple styles of structural description are supported: including describing files as unit-record (UnitSegmentLayout) files; describing cubes; and describing event-history (spell) data.

DDI 3.2 mapping

p:PhysicalDataProductType

Definition

A description of each physical storage segment required to completely cover the logical record. A logical record may be stored in one or more segments housed hierarchically in a single file or in separate data files. All logical records have at least one segment.

Examples

The file below has four InstanceVariables: PersonId, SegmentId, AgeYr, HeightCm. The data for each person (identified by PersonId) is recorded in two segments (identified by SegmentId), "a" and "b". AgeYr is on physical segment a, and HeightCm is on segment b. These are the same data as described in the UnitSegmentLayout documentation. 1 a 22 1 b 183 2 a 45 2 b 175

DDI 3.2 mapping

p:PhysicalRecordSegmentType

Definition

The PhysicalSegmentLayout is an abstract class used as an extension point in the description of the different layout styles of data structure description.

Examples

Examples include UnitSegmentLayouts, event data layouts, and cube layouts (e.g. summary data).

Explanatory notes

A PhysicalLayout is a physical description (e.g. UnitSegmentLayout) of the associated Logical Record Layout consisting of a Collection of Value Mappings describing the physical interrelationship of each related ValueMapping and associated Instance Variable.

Definition

Among other things defines the location of a DataPoint in a PhysicalSegment (e.g. the location of the representation of a variable in a text file). This is abstract since there are many different ways to describe the location of a segment - character counts, start and end times, etc.

Examples

A segment of text in a plain text file beginning at character 3 and ending at character 123.

Explanatory notes

While this has no properties or relationships of its own, it is useful as a target of relationships where its extensions may serve.

Definition

Defines the location of a segment of text through character, and optionally line, counts. An adequate description will always include a startCharacterPosition and then may include an endCharacterPosition or a characterLength. If StartLine is specified, the character counts begin within that line. An endCharacterPosition of 0 indicates that whole lines are specified

Examples

The segment beginning at line 3, character 4 and ending at line 27 character 13. Alternatively the segment beginning at character 257 and ending at character 1350 of the whole body of text. StartLine of 10, endLine of 12, startCharacterPosition of 1, endCharacterPosition of 0 means all of lines 10,11, and 12.

Definition

UnitSegmentLayout supports the description of unit-record ("wide") data sets, where each row in the data set provides the same group of values for variables all relating to a single unit. Each logical column will contain data relating to the values for a single variable.

Examples

A simple spreadsheet. Commonly the first row of the table will contain variable names or descriptions.

The following csv file has a rectangular layout and would import into a simple table in a spreadsheet: PersonId,AgeYr,HeightCm 1,22,183 2,45,175

Explanatory notes

This is the classic rectangular data table used by most statistical packages, with rows/cases/observations and columns/variables/measurements. Each cell (DataPoint) in the table is the intersection of a Unit (row) and an InstanceVariable.

Definition

Provides physical characteristics for an InstanceVariable as part of a PhysicalSegmentLayout

Examples

A variable "age" might be represented in a file as a string with a maximum length of 5 characters and a number pattern of ##0.0

Explanatory notes

An InstanceVariable has details of value domain and datatype, but will not have the final details of how a value is physically represented in a data file. A variable for height, for example, may be represented as a real number, but may be represented as a string in multiple ways. The decimal separator might be, for example a period or a comma. The string representing the value of a payment might be preceded by a currency symbol. The same numeric value might be written as “1,234,567” or “1.234567 E6”. A missing value might be written as “.”, “NA”, “.R” or as “R”. The ValueMapping describes how the value of an InstanceVariable is physically expressed. The properties of the ValueMapping as intended to be compatible with the W3C Metadata Vocabulary for Tabular Data (https://www.w3.org/TR/tabular-metadata/ ) as well as common programming languages and statistical packages. The “format” property, for example can draw from an external controlled vocabulary such as the set of formats for Stata, SPSS, or SAS.

Definition

The specification of a controlled vocabulary defines a set of values and their definitions together with the order relationships among those entries.

Definition

A set of CustomValues to be attached to some object.

Examples

A set of OMB required information about a question.

The set of openEHR protocol information to be attached to a blood pressure Capture

Definition

A custom item description. This allows the definition of an item which is a member of a CustomStructure. It defines the minimum and maximum number of occurrences and representation of a CustomValue.

Examples

DegreeOfBurden for a question as required by the U.S. OMB.

BloodPressureCuffSize - the size of a blood pressure cuff specified for a particular protocol.

Explanatory notes

This definition will be referenced by a CustomValue when recording a key,value instance

Definition

One entry term and its definition in an ordered list comprising a controlled vocabulary.

Examples

aunt - The female sibling of a parent

Definition

Generic description of a sampling algorithm expressed by a Sampling Design and implemented by a Sampling Process. May include common algebraic formula or statistical package instructions (use of specific selection models).

Examples

Random Sample; Stratified Random Sample

Definition

The Sampling Procedure describes the population being sampled, the sampling frame and the sampling plan including steps and sub steps by referencing the universe, sample frames and sampling plans described in schemes. Target sample sizes for each stage can be noted as well as the process for determining sample size, the date of the sample and the person or organization responsible for drawing the sample.

Examples

Census of Population and Housing, 1980 Summary Tape File 4, chapter on Technical Information. Overview is the Introduction generally describing the sample; there is a sample design section which provides a more detailed overview of the design. Additional external documentation provides detailed processes for sample adjustments needed for small area estimations, sample frames etc.

Explanatory notes

This is a summary of the methodology of sampling providing both an overview of purpose and use of a particular sampling approach and optionally providing specific details regarding the algorithm, design, and process of selecting a sample.

Definition

Provides the details of the process used to apply the sampling design and obtain the sample. Sampling Process contains a Workflow Step which provides the constituents of a Workflow. It can be a composition (a set of Control Constructs) or atomic (an Act) and may be performed by a service. This allows the use of existing Workflow models to express various sampling process actions. Sampling Frames and Sample Population can be used as designated Inputs or Outputs using Parameters.

Examples

A Split which takes a sampling stage and divides the sample frame into different subsets. A different sampling technique is applied to each subset. Once a split occurs each subset can have stages underneath, and the number of states under each split subset may differ. A Stage is the application of a single sampling algorithm applied to a sampling frame. For instance, the US Current Population Survey samples geographic areas first before identifying household to contact within each of those areas. A Stratification of a stage into multiple subsets. Each stratified group will be sampled using the same sampling approach. For example stratifying a state by ZIP Code areas in each of 5 mean income quintiles and then doing a random sample of the households in a set of Zip Codes. Allows for oversampling of identified subpopulations.

Definition

Study is the conceptual anchor for an individual collection activity resulting in a data set or data file. It can be both a part of a StudySeries as a wave etc. or an unrelated activity like a single survey project.

Examples

ICPSR study 35575 Americans and the Arts [1973 - 1992] (ICPSR 35575). https://www.icpsr.umich.edu/icpsrweb/ICPSR/studies/35575?dataFormat%5B0%5D=SAS&keyword%5B0%5D=public+opinion&geography%5B0%5D=United+States&searchSource=revise

Explanatory notes

The Study class brings together many properties and relationships describing a set of data – coverage, kind of data, methodology, citation information, access information and more.

DDI 3.2 mapping

s:StudyUnitType