Groups are used to document related data. They may contain subgroups or individual study items, and may also contain metadata which is applicable to all members of the group, and is subject to over-rides at the lower levels. Thus, metadata is inherited down the grouping structure. The purpose of groups is described using the attributes which summarize relationships along the dimensions of time, panel, geography, instrument and language. These attributes allow the purpose to be machine-actionable, while the group also includes an element for describing the purpose in human-readable format. The Resource is a specialized type of Group which is intended to hold re-usable metadata such as Category Schemes, Variables, etc. It is placed in the Resource construct for the purposes of being included by reference in other Groups and StudyUnits which describe studies, but does not directly describe existing studies itself. The Resource Package is a specialized structure which is intended to hold reusable metadata such as Category Schemes, Variable Schemes, etc. These are placed in the Resource Package for the purpose of being included by reference in Groups and StudyUnits. The Resource Package has a similar structure to the Group. Includes bibliographic citation information for the resource package. Human-readable summary of the material in the resource package. Human-readable explanation of why the creator grouped these objects together for reuse. When creating documentation from incomplete legacy materials this field may contain a statement such as "Unavailable", "Not provided by creator", or other similar statements. Provides information about the agency and grant(s) which funded the resource package. Documents the topical, spatial, and temporal coverage of the resource package. References the universe or sub-universe of the resource package. References other materials related to the resource package. Provides archive-specific information, including a listing of items. Notes regarding the group as a whole, or pertaining to all members of the resource package. Documents, or references, concept schemes, universe schemes, geographic structure and geographic location schemes. Reusable documentation regarding the data collection process. Reusable documentation pertaining to the logical description of data. Reusable documentation regarding a physical data product. Provides documentation regarding the comparability of various DDI resources. Contains a reusable DDI Profile. References a DDI Profile used by the resource package. Groups are used to document related data. They may contain subgroups or individual study items, and may also contain metadata which is applicable to all members of the group, and is subject to over-rides at the lower levels. Thus, metadata is inherited down the grouping structure. The purpose of groups is described using the attributes which summarize relationships along the dimensions of time, panel, geography, instrument and language. These attributes allow the purpose to be machine-actionable, while the group also includes an element for describing the purpose in human-readable format. Includes bibliographic citation information for the group. Human-readable summary of the grouped material. Human-readable explanation of why the creator grouped these objects together. Example: Grouping of Longitudinal Survey elements. Example: Collection of StudyUnits to be used by class SOC1257- Impact of Aging on Social Services. Use this element to describe the nature of a series and/or the reason for treating the included study units and/or subgroups as a group. Include information on the limitations of the grouping and intended usage if applicable. When creating documentation from incomplete legacy materials this field may contain a statement such as "Unavailable", "Not provided by creator", or other similar statements. Information regarding the official series of which a study unit or group of study units is a part. One may point to the URL of a series repository and then use the Name field to indicate the series itself as identified in that repository. Fields also exist for describing the series and providing abbreviations. Provides information about the agency and grant(s) which funded the group. Documents the topical, spatial, and temporal coverage of the group. References the universe or sub-universe of the group. References other materials related to the group. Provides archive-specific information, including a listing of items. Notes regarding the group as a whole, or pertaining to all members of the group. Lists, or references, the concepts describing the data that are being documented. Shared documentation regarding data collection for all members of the group, subject to overrides at a lower level. Shared documentation regarding the logical data products of all members of the group, subject to overrides at a lower level. Shared documentation regarding physical data products of all members of the group, subject to overrides at a lower level. Description of an individual study being documented as a member of the group. The study unit description inherits all metadata found at higher levels - that is, all metadata and documentation describing the groups and subgroups of which the study unit is a member. This metadata and documentation may be over-ridden within the study unit. Subordinate group which inherits all the metadata provided in the higher-level groups and subgroups of which this subgroup is a member, subject to overrides within the subgroup itself. Provides documentation regarding the comparability of study units or subgroups within the containing group. Contains a DDI Profile which is used by the group, and which can be referenced externally. If contained in a ResourcePackage, it is intended only for reuse elsewhere. References a DDI Profile used by the group or resource package. Indicates how all members of the group are related along the dimension of time (for example single occurrence, multiple occurrence, etc.). Indicates how all members of the group are related in terms of the instruments used to collect data (single, multiple, etc.). Indicates how all members of the group are related in terms of type of panel (single, rolling, etc.). Indicates how all members of the group are related along the dimension of geography. Indicates how all members of the group are related in terms of physical data products in relation to data collection efforts. Indicates how all members of the group are related in terms of physical data products in relation to data collection efforts. Provides a user-defined grouping property, different from those supplied in other attributes. Provides a value for the user-defined group property supplied in userDefinedGroupProperty. Default is true, and allows for inheritance of all properties and modules, and the use of lower-level over-rides. If set to false, inheritance is switched off for specific groups. The subgroup element is a container for a group that is a child of a higher-level group described in this module, but may also be a parent to other (subordinate) groups. A group can be fully described, or just referenced, within its subgroup container. Includes bibliographic citation information for the group. Human-readable summary of the grouped material. Human-readable explanation of why the creator grouped these objects together. Example: Grouping of Longitudinal Survey elements. Example: Collection of StudyUnits to be used by class SOC1257- Impact of Aging on Social Services. Use this element to describe the nature of a series and/or the reason for treating the studyunits as a group. Include information on the limitations of the grouping and intended usage if applicable. Information regarding the official series of which a study unit or group of study units is a part. You may point to the URL of a series repository and then use the Name field to indicate the series itself as identified in that repository. Fields also exist for describing the series and providing abbreviations. Provides information about the agency and grant(s) which funded the group. Documents the topical, spatial, and temporal coverage of the group. References the universe or sub-universe of the group. References other materials related to the group. Provides archive-specific information, including a listing of items. Notes regarding the group as a whole, or pertaining to all members of the group. Lists, or references, the concepts describing the data that are being documented. Shared documentation regarding data collection for all members of the group, subject to over-rides at a lower level. Shared documentation regarding the logical data products of all members of the group, subject to over-rides at a lower level. Shared documentation regarding physical data products of all members of the group, subject to over-rides at a lower level. Description of an individual study being documented as a member of the group. The study unit description inherits all metadata found at higher levels - that is, all metadata and documentation describing the groups and subgroups of which the study unit is a member. This metadata and documentation may be over-ridden within the study unit. Provides documentation regarding the comparability of study units or subgroups within the containing group. Contains a DDI Profile which is used by the group, and which can be referenced externally. If contained in a ResourcePackage, it is intended only for re-use elsewhere. References a DDI Profile used by the group or resource package. Includes fully detailed, in-line information about a group that is the child of a higher-level group described in this module. References a sub-group that is the child of a higher-level group or sub-group described in this module. Indicates how all members of the group are related along the dimension of time (for example single occurrence, multiple occurrence, etc.). Indicates how all members of the group are related in terms of the instruments used to collect data (single, multiple, etc.). Indicates how all members of the group are related in terms of type of panel (single, rolling, etc.). Indicates how all members of the group are related along the dimension of geography. Indicates how all members of the group are related in terms of physical data products in relation to data collection efforts. Indicates how all members of the group are related in terms of physical data products in relation to data collection efforts. Provides a user-defined group property, different from those supplied in other attributes. Provides a value for the user-defined group property supplied in userDefinedGroupProperty. Default is true, and allows for inheritance of all properties and modules, and the use of lower-level over-rides. If set to false, inheritance is switched off for specific groups. Allows for inclusion of a fully marked up Conceptual Components module or referencing such a module that is external to the instance. Lists, or references, the concepts describing the data that are being documented. References a Conceptual Components module that is external to the group. Allows for inclusion of data collection information that is common to all members of the group, or referencing external data collection information. Includes data collection information that is common to all members of the group. References external data collection information. Allows for inclusion of a logical product that is common to all members of the group, or referencing an external logical product. Contains a logical product that is common to all members of the group. References an external logical product module. Allows for inclusion of a physical data product for reuse by reference. Contains a physical data product module. References an external physical data product module. Allows for inclusion of a study unit that belongs to the group as a direct child. Subgroups may also contain study units, and individual study units and subgroups may be members of a single group. Study units can be included in any group or subgroup either as in-line documentation/metadata or by reference. Contains the detailed documentation for a study unit which is a member of the group. References a study unit which is a member of the group, but is documented in a different DDI metadata set. Indicates how all members of the group are related along the dimension of time. These relationships are inferred by the markup author, and should be considered as her/his own interpretation of the data. No specified relationship Single Occurrence Multiple Occurrence: Regular Occurrence: Continuing Multiple Occurrence: Regular Occurrence: Limited time Multiple Occurrence: Irregular Occurrence: Continuing Multiple Occurrence: Irregular Occurrence: Limited time Indicates how all members of the group are related in terms of the instruments used to collect data. These relationships are inferred by the markup author, and should be considered as her/his own interpretation of the data. No specified relationship Single Multiple: Integrated set of 2 or more instruments used for different subpopulations Multiple: Base with Topical changes Indicates how all members of the group are related in terms of type of panel. These relationships are inferred by the markup author, and should be considered as her/his own interpretation of the data. No specified relationship Single panel surveyed multiple times Single panel surveyed once Rolling panel Different panel each survey Indicates how all members of the group are related along the dimension of geography. These relationships are inferred by the markup author, and should be considered as her/his own interpretation of the data. No specified relationship Single geography surveyed multiple times Single geography surveyed once Rolling geography Different geography each survey Indicates how all members of the group are related in terms of physical data products in relation to data collection efforts. These relationships are inferred by the markup author, and should be considered as her/his own interpretation of the data. No specified relationship Single data file from a data collection Multiple data products from a single data collection Integration of multiple data sets into a single integrated structure Multiple data files each from a different data collection Indicates the panel relationships among all Study Units within the group and its sub-groups. This is an assertion of the relationship, and it is incumbent on the creating user or application to make sure that the assertion is true. No formal relationship - not a factor of grouping Single language All original languages with full language equivalence Original language(s) plus translation(s) with full language equivalence Translations from external original; full language equivalence Translations from a non-included original and have full language equivalence Original languages(s) plus translation(s) with partial relationship Translations from external original; partial relationships Human-readable summary of the grouped material. Human-readable explanation of why the creator published these objects. Lists, or references, the concepts describing the data that are being documented. Shared documentation regarding data collection for all members of the group, subject to over-rides at a lower level. Shared documentation regarding the logical data products of all members of the group, subject to over-rides at a lower level. Shared documentation regarding the physical data products of all members of the group, subject to over-rides at a lower level. Description of an individual study being documented as a member of the group. The study unit description inherits all metadata found at higher levels - that is, all metadata and documentation describing the groups and subgroups of which the study unit is a member. This metadata and documentation may be over-ridden within the study unit. Subordinate group which inherits all the metadata provided in the higher-level groups and subgroups of which this subgroup is a member, subject to over-rides within the sub-group itself. References a DDI Profile used by the group or resource package. References a module that is external to the group, sub-group, or resource package.