This is a w3c Schema "Technical Implementation" of the DDI Conceptual Specification.

Target Namespace:

Defined Components:

Default Namespace-Qualified Form:

Schema Location:

Imports Schemas (3):

Location of Data Collection Description Location where the data collection is currently stored.

Actions to Minimize Losses Description Summary of actions taken to minimize data loss.

Alternative Title Description A title by which the work is commonly referred, or an abbreviation of the title.

Data Appraisal Description Information on data appraisal.

Analysis Unit Description Provides information regarding whom or what the variable/nCube describes.

Unit of Analysis Description Basic unit of analysis or observation that the file describes: individuals, families/households, groups, institutions/organizations, administrative units, etc.

Attribute Description Identifies an attribute within the element(s) identified by the selector or specificElements in which the controlled vocabulary is used.

Authoring Entity/Primary Investigator Description The person, corporate body, or agency responsible for the works substantive and intellectual content.

Authorization Statement Description The text of the authorization.

Authorizing Agency Description Name of the agent or agency that authorized the study.

Availability Status Description Statement of collection availability.

Backflow Description Contains a reference to IDs of possible preceding questions.

Bibliographic Citation Description Complete bibliographic reference containing all of the standard elements of a citation that can be used to cite the work.

Geographic Bounding Polygon Description This field allows the creation of multiple polygons to describe in a more detailed manner the geographic area covered by the dataset.

Number of cases / Record Quantity Description Number of cases or observations.

Category Description A description of a particular response.

Category Group Description A description of response categories that might be grouped together.

Category Level Description Used to describe the levels of the category hierarchy.

Category Level Statistic Description May include frequencies, percentages, or crosstabulation results.

Category Value Description The explicit response option for a category.

Bibliographic Citation Description This element encodes the bibliographic information for the work at the level specified

Citation Requirement Description Text of requirement that a data collection should be cited properly in articles or other publications that are based on analysis of the data.

Cleaning Operations Description Methods used to "clean" the data collection, e.g., consistency checking, wild code checking, etc.

Codebook Description Every element in the DDI DTD/Schema has the following attributes

Code List Agency Name Description Agency maintaining the code list.

Code List ID Description Identifies the code list that the value is taken from.

Code List Name Description Identifies the code list that the value is taken from with a human-readable name.

Code List Scheme URN Description Identifies the code list scheme using a URN.

Code List URN Description Identifies the code list that the value is taken from with a URN.

Code List Version ID Description Version of the code list.

Coding Instructions Description Describe specific coding instructions used in data processing, cleaning, acquisition, or tabulation.

Coder Instructions Description Any special instructions to those who converted information from one form to another for a particular variable.

Cohort Description The element cohort is used when the nCube contains a limited number of categories from a particular variable, as opposed to the full range of categories.

Date of Collection Description Contains the date(s) when the data were collected.

Collector Training Description Describes the training provided to data collectors including interviewer training, process testing, compliance with standards etc.

Mode of Data Collection Description The method used to collect the data; instrumentation characteristics.

Characteristics of Data Collection Situation Description Description of noteworthy aspects of the data collection situation.

Extent of Collection Description Summarizes the number of physical files that exist in a collection, recording the number of files that contain data and noting whether the collection contains machine-readable documentation and/or other supplementary files and information such as data dictionaries, data definition statements, or data collection instruments.

Column Specification

Command Description Provide command code for the coding instruction.

Completeness of Study Stored Description This item indicates the relationship of the data collected to the amount of data coded and stored in the data collection.

Concept Description The general subject to which the parent element may be seen as pertaining.

Conditions Description Indicates any additional information that will assist the user in understanding the access and use conditions of the data collection.

Confidentiality Declaration Description This element is used to determine if signing of a confidentiality declaration is needed to access a resource.

Control Operations Description Methods to facilitate data control performed by the primary investigator or by the data archive.

Contact Persons Description Names and addresses of individuals responsible for the work.

Controlled Vocabulary Used Description Provides information on the use of a controlled vocabulary by the DDI instance.

Copyright Description Copyright statement for the work at the appropriate level.

Cube Coordinate Description This is an empty element containing only the attributes listed below.

Custodian Description Custodian identifies the agency or individual who is responsible for creating or maintaining the sample frame.

Data Access Description This section describes access conditions and terms of use for the data collection.

Other Forms of Data Appraisal Description Other issues pertaining to data appraisal.

Extent of Processing Checks Description Indicate here, at the file level, the types of checks and operations performed on the data file.

Data Collection Methodology Description Information about the methodology employed in a data collection.

Data Collector Description The entity (individual, agency, or institution) responsible for administering the questionnaire or interview or compiling the data.

Variable Description Description Description of variables, variable groups, nCubes, and nCube groups.

Data Fingerprint Description Allows for assigning a hash value (digital fingerprint) to the data or data file.

Data Item Description Identifies a physical storage location for an individual data entry, serving as a link between the physical location and the logical content description of each data item.

Kind of Data Description The type of data included in the file: survey data, census/enumeration data, aggregate data, clinical data, event/transaction data, program source code, machine-readable text, administrative records data, experimental data, psychological test, textual data, coded textual, coded documents, time budget diaries, observation data/ratings, process-produced data, etc.

Missing Data Description This element can be used to give general information about missing data, e.g., that missing data have been standardized across the collection, missing data are present because of merging, etc.

Data Processing Description Describes various data processing procedures not captured elsewhere in the documentation, such as topcoding, recoding, suppression, tabulation, etc.

Data Sources Description Used to list the book(s), article(s), serial(s), and/or machine-readable data file(s)--if any--that served as the source(s) of the data collection.

Definition Description Rationale for why the group was constituted in this way.

Date of Deposit Description The date that the work was deposited with the archive that originally received it.

Depositor Description The name of the person (or institution) who provided this work to the archive storing it.

Deposit Requirement Description Information regarding user responsibility for informing archives of their use of data through providing citations to the published work or providing copies of the manuscripts.

Derivation Description Used only in the case of a derived variable, this element provides both a description of how the derivation was performed and the command used to generate the derived variable, as well as a specification of the other variables in the study used to generate the derivation.

Development Activity Description Information on the development activity including a "description" of the activity, name of each "participant", each "resource" used, and each "outcome" of the activity.

Major Deviations from the Sample Design Description Information indicating correspondence as well as discrepancies between the sampled units (obtained) and available statistics for the population (age, sex-ratio, marital status, etc.) as a whole.

File Dimensions Description Dimensions of the overall file.

Disclaimer Description Information regarding responsibility for uses of the data collection.

Date of Distribution Description Date that the work was made available for distribution/presentation.

Distributor Description The organization designated by the author or producer to generate copies of the particular work including any necessary editions or revisions.

Distributor Statement Description Distribution statement for the work at the appropriate level: marked-up document; marked-up document source; study; study description, other material; other material for study.

Division Description Formatting element: marks a subdivision in a text.

Dimension Description This element defines a variable as a dimension of the nCube, and should be repeated to describe each of the cube's dimensions.

Document Description Description The Document Description consists of bibliographic information describing the DDI-compliant document itself as a whole.

Documentation Source Description Citation for the source document.

Documentation Status Description Use this field to indicate if the documentation is being presented/distributed before it has been finalized.

Derivation Command Description The actual command used to generate the derived variable.

Derivation Description Description A textual description of the way in which this variable was derived.

East Bounding Longitude Description The easternmost coordinate delimiting the geographic extent of the dataset.

Embargo Description Provides information on variables/nCubes which are not currently available because of policies established by the principal investigators and/or data producers.

Emphasis Description Formatting element: marks words or phrases that are emphasized for rhetorical effect.

Table Entry

Estimates of Sampling Error Description Measure of how precisely one can estimate a population value from a given sample.

Evaluation Process Description Describes the evaluation process followed.

Evaluator Type Description The evaluator element identifies persons or organizations involved in the evaluation process.

Post Evaluation Procedures Description Use this section to describe evaluation procedures not address in data evaluation processes.

External Link Description This element permits encoders to provide links from any arbitrary element containing ExtLink as a subelement to electronic resources outside the codebook.

File Citation Description The complex element fileCitation provides for a full bibliographic citation option for each data file described in fileDscr.

File Command Description The element allows for the description of the file command by capturing a textual description of the command including the capture of pseudo code in "drvdesc" as well as the specific command using "drvcmd".

Contents of Files Description Abstract or description of the file.

File Derivation Description The element allows for the description of the file commands used to creation the file derivation.

File Derivation Variables Description Empty element consisting only of its attributes.

Data Files Description Description Information about the data file(s) that comprises a collection.

File Name Description Contains a short title that will be used to distinguish a particular file/part from other files/parts in the data collection.

Place of File Production Description Indicates where the file was produced.

Number of Files Description Total number of physical files associated with a collection.

File Structure Description Type of file structure.

File-by-File Description Description Provides descriptive information about the data file.

Type of File Description Types of data files include raw data (ASCII, EBCDIC, etc.) and software-dependent files such as SAS datasets, SPSS export files, etc.

Data Format Description Physical format of the data file: Logical record length format, card-image format (i.e., data with multiple records per case), delimited format, free format, etc.

Forward Progression Description Contains a reference to IDs of possible following questions.

Frame Unit Description Provides information about the sampling frame unit.

Frequency of Data Collection Description For data collected at more than one point in time, the frequency with which the data were collected.

Funding Agency/Sponsor Description The source(s) of funds for production of the work including abbreviation and affiliation.

General Data Format Description Expresses the variety of data formats covered i.e.

Geographic Bounding Box Description The fundamental geometric description for any dataset that models geography.

Geographic Coverage Description Information on the geographic coverage of the data.

Geographic Unit Description Lowest level of geographic aggregation covered by the data.

Geographic Map Description Empty element consisting only of its attributes.

Grant Number Description The grant/contract number of the project that sponsored the effort.

G-Ring Latitude Description Latitude (y coordinate) of a point.

G-Ring Longitude Description Longitude (x coordinate) of a point.

Guide to Codebook Description List of terms and definitions used in the documentation.

Head Description Formatting element: marks off a heading to a division, list, etc.

Highlight Description Formatting element: marks a word or phrase as graphically distinct from the surrounding text, while making no claim for the reasons.

Holdings Information Description Information concerning either the physical or electronic holdings of the cited work.

Identification Number Description Unique string or number (producer's or archive's number).

Imputation Description According to the Statistical Terminology glossary maintained by the National Science Foundation, this is "the process by which one estimates missing values for items that a survey respondent failed to provide," and if applicable in this context, it refers to the type of procedure used.

Instrument Development Description Describe any development work on the data collection instrument.

Range of Invalid Data Values Description Values for a particular variable that represent missing data, not applicable responses, etc.

Value Item Description The counterpart to Range; used to encode individual values when the values cannot be expressed as a min/max range or when specification of the values is desired.

Item Description Formatting element: marks entries (items) in a list.

Interviewer Instructions Description Specific instructions to the individual conducting an interview.

Range Key Description This element permits a listing of the category values and labels.

Keywords Description Words or phrases that describe salient aspects of a data collection's content.

Label Description Formatting element: contains the label associated with an item in a list; in glossaries, marks the term being defined.

Label Description A short description of the parent element.

Language Description A brief textual identification of the language of the cited object.

License Description A legal document giving official permission to something with the resource.

Link Description This element permits encoders to provide links from any arbitrary element containing Link as a subelement to other elements in the codebook.

List Description Formatting element: contains any sequence of items (entries) organized as a list.

Location Description Empty element consisting only of its attributes.

Location Map Description This element maps individual dataItems to one or more physical storage locations.

Logical Record Length Description Logical record length, i.e., number of characters of data in the record.

Measure Description Empty element consisting only of its attributes.

Metadata Access Description This section describes access conditions and terms of use for the metadata.

Methodology and Processing Description This section describes the methodology and processing involved in a data collection.

Mathematical Identifier Description Token element containing the smallest unit in the mrow that carries meaning expressed by the attribute varRef.

Mathematical Row Description This element is a wrapper containing the presentation expression mi.

Country Description Indicates the country or countries covered in the file.

nCube Description Describes the logical structure of an n-dimensional array, in which each coordinate intersects with every other dimension at a single point.

nCube Group Description A group of nCubes that may share a common subject, arise from the interpretation of a single question, or are linked by some other factor.

North Bounding Latitude Description The northernmost coordinate delimiting the geographic extent of the dataset.

Notes and comments Description For clarifying information/annotation regarding the parent element.

Archive Where Study Originally Stored Description Archive from which the data collection was obtained; the originating archive.

Other Study-Related Materials Description This section allows for the inclusion of other materials that are related to the study as identified and labeled by the DTD/Schema users (encoders).

Other Identifications /Acknowledgments Description Statements of responsibility not recorded in the title and statement of responsibility areas (collaborators).

Other References Notes Description Indicates other pertinent references.

Other Study Description Materials Description Other materials relating to the study description.

Evaluation Outcomes Description Describe the outcomes of the evaluation.

Paragraph Description Marks a paragraph.

Participant Description Name of "participant" in the activity being described in the parent element.

Parallel Title Description Title translated into another language.

Physical Location Description Empty element consisting only of its attributes.

Point Description 0-dimensional geometric primitive, representing a position, but not having extent.

Polygon Description The minimum polygon that covers a geographical area, and is delimited by at least 4 points (3 sides), in which the last point coincides with the first point.

PostQuestion Text Description Text describing what occurs after the literal question has been asked.

PreQuestion Text Description Text describing a set of conditions under which a question might be asked.

Processing Status Description Processing status of the file.

Date of Production Description Date when the marked-up document/marked-up document source/data collection/other material(s) were produced (not distributed or archived).

Place of Production Description Address of the archive or organization that produced the work.

Production Statement Description Part of citation including language, producer, copyright, license, prodDate, prodPlac, software, fundAg, and grantNo.

Producer Description The producer is the person or organization with the financial or administrative responsibility for the physical processes whereby the document was brought into existence.

Purpose Description Explains the purpose for which a particular nCube was created.

Question Description The question element may have mixed content.

Literal Question Description Text of the actual, literal question asked.

Quality Statement Description This structure consists of two parts, "standardsCompliance" and "otherQualityStatements".

Value Range Description Empty element consisting only of its attributes, containing the actual range of values.

Dimensions (of record) Description Information about the physical characteristics of the record including the number of variables (varQnty), number of cases (caseQnty), and record length (logRecL).

Record or Record Group Description Used to describe record groupings if the file is hierarchical or relational.

Overall Number of Records Description Overall record count in file.

Records per Case Description Records per case in the file.

Reference Period Description Indicates the period of time in which the sampling frame was actually used for the study in question.

Related Materials Description Describes materials related to the study description, such as appendices, additional information on sampling found in other documents, etc.

Related Publications Description Bibliographic and access information about articles and reports based on the data in this collection.

Related Studies Description Information on the relationship of the current data collection to others (e.g., predecessors, successors, other waves or rounds) or to other editions of the same file.

Type of Research Instrument Description The type of data collection instrument used.

Resource Description Resource provides the means of describing an external data source including a "typeOfDataSrc" which supports othe use of an external controllec vocabulary.

Response Rate Description The percentage of sample members who provided information.

Response Unit Description Provides information regarding who is intended to provide the information contained within the variable/nCube, e.g., respondent, proxy, interviewer.

Restrictions Description Any restrictions on access to or use of the collection such as privacy certification or distribution restrictions should be indicated here.

Table Row

Responsibility Statement Description Part of citation covering author (AuthEnty) and collaborators (othID).

Sample Frame Description Sample frame describes the sampling frame used for identifying the population from which the sample was taken.

Sample Frame Name Description Name of the sample frame.

Sample Size Description This element provides the targeted sample size in integer format.

Sample Size Formula Description This element includes the formula that was used to determine the sample size.

Sampling Procedure Description The type of sample and sample design used to select the survey respondents to represent the population.

Security Description Provides information regarding levels of access, e.g., public, subscriber, need to know.

Selector Description Identifies a collection of elements in which a controlled vocabulary is used.