StudyUnit
A primary packaging and publication module within DDI representing the purpose, background, development, data capture, and data products related to a study. In DDI a study is defined as a single coordinated set of data collection/capture activities, such as a one-time survey or a single iteration of a multi-year repeated study (such as one year of a longitudinal survey). The StudyUnit brings together all of the components of the study including the description of its purpose, funding, quality statements, data collection and capture methods and activities, processing activities, and a description of the resulting data (description of its intellectual or logical content plus a description of its physical store). A study unit may have only a single data collection or capture process resulting in one or more data products (i.e., Census). A complex study unit may contain multiple means of data capture that are integrated into one or more data products (i.e., a medical study collecting bio-markers, patient background, health care service information, etc.). A longitudinal study with multiple waves or iterations of data collection is considered to be a group of studies, each wave or iteration captured as a single study unit. As a primary packaging module, the Study Unit contains a full citation, abstract, authorization information, a universe reference, series statement, quality statement, information on post study evaluation, funding information, budget, purpose, coverage, type of analysis units covered, kind of data, other materials, a list of required resource packages, embargoes, the conceptual components (universe, concept, data element, geographic structure and locations), data collection, logical products, physical data products, physical instance, archive, and DDI profile. The maintainable elements within a Study Unit may be included in-line or by reference.
Properties
Name |
Type |
Description |
|
|---|---|---|---|
TypeOfStudyUnit |
0..1 |
A brief textual identification of the StudyUnit. Supports the use of an external controlled vocabulary. |
|
Citation |
0..1 |
The citation for the study. DDI strongly recommends that at minimum a Title be provided. |
|
Abstract |
0..1 |
An abstract of the study unit describing the nature and scope of the data collection, special characteristics of its content. Note that detailed information on the purpose of the study and structured coverage information are to be entered in Purpose and Coverage. Abstract supports multiple language versions of the same content as well as optional formatting of the content. |
|
AuthorizationSource |
0..n |
Identifies the authorizing agency for the study and allows for the full text of the authorization (law, regulation, or other form of authorization). May be used to list authorizations from oversight committees and other regulatory agencies. |
|
ApprovalReviewReference |
0..1 |
Provides information about the Approval Review undertaken in relation to the activity. Identifies the organization processing the review, the role of the approval review organization, case number, description, and related dates. Allows the inclusion of a reference to an external source detailing the approval review. |
|
DefiningConceptReference |
0..1 |
A concept that defines or aids in understanding the content of the study unit. |
|
UniverseReference |
0..1 |
Reference to the universe statement from the universe scheme, describing the group of persons or other elements that are the object of research and to which any analytic results refer. Age, nationality, and residence commonly help to delineate a given universe, but any of a number of factors may be involved, such as sex, race, income, veteran status, criminal convictions, etc. The universe may consist of elements other than persons, such as housing units, court cases, deaths, countries, etc. In general, it should be possible to tell from the description of the universe whether a given individual or element (hypothetical or real) is a member of the population under study. A universe may be described as “inclusive” or “exclusive”. This StudyUnit level reference is normally to the top level of the UniverseScheme. |
|
SeriesStatement |
0..n |
A study, particularly one in a series, may be the result of two series merging into a single study. The new study belongs to both series. For example, Niger now fields the UNICEF Multiple Indicators Cluster Survey (MICS) and the Demographic and Health Survey as a single merged instrument. |
|
InformationClassificationReference |
0..n |
Used to describe the rules and guidelines on how the data is allowed to be handled, transferred, stored and disposed. These confidentiality policies are often dictated by national laws and/or data owners on handling of personal, proprietary, and other sensitive information. |
|
QualityStatementReference |
0..n |
A reference to a Quality Statement pertaining to the quality of the study overall, metadata, or data to which it is associated. Quality statements may be related to external quality standards. |
|
QualitySchemeReference |
0..n |
A scheme containing statements of quality related to the quality of methodologies, metadata, or data. Quality statements and standards may be related to external quality standards. |
|
ExPostEvaluation |
0..n |
An evaluation of the study process, often taking place after the completion of the study. These may include issues such as timing of the study, sequencing issues, cost/budget issues, relevance, institutional or legal arrangements etc. of the study. If the study is part of a series or group (i.e., a single wave in a longitudinal study) this may include evaluation of earlier waves which resulted in changes to the current wave. |
|
FundingInformation |
0..n |
Contains details of the study unit’s funding, including information about grants, agencies, etc. |
|
StudyBudget |
0..n |
This describes the overall budget of the study. It can be repeated for distinct budget activities. It contains a structured description and one or more budget documents described by an OtherMaterial type. |
|
Purpose |
0..1 |
The purpose of the study, why the study took place. This should include detailed information on the investigator’s primary study questions or hypotheses as well as information on any legal basis for the data collection, such as laws requiring the collection of census data for apportionment purposes. Legal or other authorization should be provided in detail within AuthorizationSource. Supports multiple language versions of the same content as well as optional formatting of the content. |
|
Coverage |
0..1 |
Describes the coverage of the study unit. Detailed information on Topical, Temporal, and Spatial Coverage is contained here. Note that Coverage at this level should be inclusive all lower level modules or section. Lower level descriptions serve to constrain coverage within the scope described here. |
|
AnalysisUnit |
0..n |
Allows the use of a controlled vocabulary to list all of the units of analysis used in the study. Should be repeated to describe multiple units of analysis. The DDI Alliance has provided a controlled vocabulary (AnalysisUnit) to support this element at http://www.ddialliance.org/controlled-vocabularies. |
|
AnalysisUnitsCovered |
0..1 |
A narrative of the units of analysis in the study unit. Uses an InternationalString to support multiple languages. |
|
KindOfData |
0..n |
Briefly describes the kind of data documented in a study unit. Examples include survey data, census/enumeration data, administrative data, measurement data, assessment data, demographic data, voting data, etc. Supports the use of an external controlled vocabulary. |
|
GeneralDataFormat |
0..n |
Briefly describes the data formats documented in the logical product(s) of a study unit. Examples include Numeric, Text, Audio, Visual, Geospatial, StillImage, Software, 3D, etc. Supports the use of an external controlled vocabulary. The DDI Alliance has provided a controlled vocabulary (GeneralDataFormat) to support this element at http://www.ddialliance.org/controlled-vocabularies. |
|
RequiredResourcePackages |
0..1 |
Specifies by reference the ResourcePackages required to resolve the Study. This list is informational and assists in creating full transmissions of metadata or creating archival packages. Primarily used after the instance is relatively stable and published. |
|
Embargo |
0..n |
Embargo information about the study unit. References to embargo information in this section can be made from individual variables. |
|
OtherMaterialSchemeReference |
0..n |
This scheme contains a set of other materials referenced by the metadata. |
|
ConceptualComponentReference |
0..n |
Documents the content and relational structure of the concepts, universes, data elements, geographic structures and geographic locations used by the study unit. |
|
DataCollectionReference |
0..n (Ordered) |
Documents the content of the Data Collection activities used in this study; development of data collection processes, questions, question flows (control constructs), data collection instrument, instructions, processing events and instructions, methodology, etc. |
|
LogicalProductReference |
0..n |
Documents the logical (intellectual) content of the data produced by the study unit. Note that l:BaseLogicalProduct is the head of a substitution group and is replaced by the appropriate member of that substitution group. |
|
PhysicalDataProductReference |
0..n |
Documents the physical structure of the data produced by the study unit. |
|
PhysicalInstanceReference |
0..n |
Documents the link to a specific external data file produced by the study unit. May contain summary and category level statistics on the variables contained in the data file. |
|
PhysicalInstanceGroupReference |
0..n |
Allows physical instance modules to be grouped with or without hierarchical structure. |
|
ArchiveReference |
0..n |
Archive serves as a packet containing both persistent and transient information. Describes archive-specific material including item record information as well as lifecycle information. The metadata in the package is divided into elements that are persistent (should remain with the Study Unit through its life-cycle), and transient (pertinent only to the Study Unit as held by that archive). |
|
ClassificationFamilyReference |
0..n |
Allows for in-line entry of a Classification Family. |
|
DDIProfileReference |
0..n |
Contains a DDI Profile which is used by the study unit. |
Properties Inherited from Maintainable
Name |
Type |
Description |
|
|---|---|---|---|
Note |
0..n |
Note allows for the attachment of a piece of additional information to any object with an ID. Note facilitates capturing temporary processing notes such as “Review and approval required”. A single note can be attached to multiple objects by reference to the objects. Note may also contain content for a needed object that has been reported for addition in a later version of the schema. Ideally this should be handled by a local extension, but Note can accommodate run-time extensions when required. The Note should be housed within the Maintainable object that contains the referenced objects. In this way the user is ensured of receiving all known Note attachments when the maintainable content is delivered. This means that if a Note references objects within multiple Maintainable objects, the Note should be repeated in each Maintainable and reference only those objects with that Maintainable. |
|
Software |
0..n |
Indicate the software used to create and/or manage the metadata. This is repeatable to allow for multiple softwares or multiple functions. If this information is important it is advisable to provide it in each maintainable so that it does not become separated from the internal content if the metadata is re-factored. |
|
MetadataQuality |
0..n |
An assessment of the quality of the metadata within the Maintainable object, e.g. the quality of the transcription, completeness, editing status, etc. |
|
ExternalReferenceDefaultURI |
0..1 |
Use to provide a default value for the URI of external references. Use of a URI in a reference within this maintainable overrides the value entered here. Nested maintainables should redeclare the contents of this attribute for clarity. |
|
Lang |
0..1 |
This is used to designate the language of the metadata content of the maintainable. If a lower level xml:lang attribute conflicts with the content at the maintainable level, the object level value takes precedence. |
Properties Inherited from Versionable
Name |
Type |
Description |
|
|---|---|---|---|
URN |
1..1 |
||
Agency |
1..1 |
||
ID |
1..1 |
||
Version |
1..1 |
||
UserID |
0..n |
Allows for the specification of identifiers other than the specified DDI identification of the object. This may be a legacy ID from DDI-C, a system specific ID such as for a database or registry, or a non-DDI unique identifier. As the identifier is specific to a system the system must be identified with the UserID structure. |
|
UserAttributePair |
0..n |
A system specific user defined property of the object expressed as a key/value pair. As this is specific to an individual system the use of controlled vocabularies for the key is strongly recommended. |
|
VersionResponsibility |
0..1 |
Person or organization within the MaintenanceAgency responsible for the version change. If it is important to retain the affiliation between and individual responsible for the version and his/her agency, it may be included in this notation. This is primarily intended for internal use. |
|
VersionResponsibilityReference |
0..1 |
Reference person or organization within the MaintenanceAgency responsible for the version change, as described in an OrganizationScheme. If it is important to retain the affiliation between and individual responsible for the version and his/her agency, a Relation should be created between the individual referenced here and his/her organization. This is primarily intended for internal use. |
|
VersionRationale |
0..1 |
Textual description of the rationale/purpose for the version change and a coded value to provide an internal processing flag within and organization or system. Note that versioning can only take place on objects owned by the specified DDI Agency. If you are creating a local instance of an object from another agency for current or future modification use BasedOnObject. If the changes being made result in what you determine to be new object rather than a version of a previous object, i.e. the change is too extensive to consider it a version of the existing object, create a new object and use BasedOnObject to provide a link to the object or objects that were a basis for the new object. |
|
BasedOnObject |
0..1 |
Use when creating an object that is based on an existing object or objects that are managed by a different agency or when the new object is NOT simply a version change but you wish to maintain a reference to the object that served as a basis for the new object. BasedOnObject may contain references to any number of objects which serve as a basis for this object, a BasedOnRationalDescription of how the content of the referenced object was incorporated or altered, and a BasedOnRationalCode to allow for specific typing of the BasedOnReference according to an external controlled vocabulary. |
|
RelatedOtherMaterialReference |
0..n |
The inclusion of an existing OtherMaterial by reference. Use for any type of OtherMaterial not specifically addressed by an inline description for such as ExternalAid in QuestionItem. |
|
VersionDate |
0..1 |
Date of version using the union set BaseDateType. Duration should not be used in this field, even though allowed by the ISO format enforced by the parser. |
|
IsPublished |
0..1 |
Indicates that the maintainable will not be changed without versioning, and is a stable target for referencing. |
Item Type Hierarchy
- Versionable
- Maintainable
StudyUnit
Relationships
The following identified item types reference this type.
Item Type |
Property |
|---|---|
StudyUnitReference |
|
SourceSchemeReference |
|
StudyUnitReference |
|
DepositoryStudyUnitReference |
