Data Documentation Data Documentation Initiative (DDI)Initiative (DDI)

WorkshopWorkshop

Carol PerryCarol PerryErnie BoykoErnie Boyko

April 2005April 2005Kingston OntarioKingston Ontario

Workshop objectivesWorkshop objectives

• To make participants more familiar To make participants more familiar with the concept of marking up data with the concept of marking up data documentation using DDI tags in the documentation using DDI tags in the DDI XML based Document type DDI XML based Document type Definition (DTD)Definition (DTD)

Workshop OutlineWorkshop Outline

• Review of last year’s DDI presentationReview of last year’s DDI presentation

• ObjectivesObjectives for this year for this year

• Work groupsWork groups

• AssignmentAssignment– TaskTask– Working MaterialWorking Material

• Reporting BackReporting Back

• Wrap-upWrap-up

Last year….Last year….

• What is DDI?What is DDI?

• Why DDI?Why DDI?

• Some ‘how to’s’Some ‘how to’s’

• Some ExamplesSome Examples

In a nut shell….In a nut shell….•The Data Documentation Initiative is

an international effort to establish a standard for technical documentation describing social science data

• Intended to make codebooksIntended to make codebooks– ‘‘Processible’Processible’– ‘‘Preservable’Preservable’– ‘‘Interoperable’Interoperable’

http://http://www.icpsr.umich.edu/DDI/index.htmlwww.icpsr.umich.edu/DDI/index.html

DTD - Document Type DTD - Document Type DefinitionDefinition

• Consists of a Tag Library Consists of a Tag Library

• Tags have been developed by DDITags have been developed by DDI

• A set of tags, when filled, are known A set of tags, when filled, are known as a codebookas a codebook

• DDI – intends to comply to Dublin DDI – intends to comply to Dublin CoreCore

TagsTags

• Tags present English language Tags present English language descriptions of XML (eXtensible descriptions of XML (eXtensible Markup Language)Markup Language)

• Each tag can be optional or Each tag can be optional or mandatory, repeatable or non-mandatory, repeatable or non-repeatablerepeatable

• Set of tags for each section of DTDSet of tags for each section of DTD

5 Sections of DTD5 Sections of DTD ((DocumentDocument Type DefinitionType Definition))

• 1.0 Document Description1.0 Document Description

• 2.0 Study Description2.0 Study Description

• 3.0 Data File Description3.0 Data File Description

• 4.0 Variables Description4.0 Variables Description

• 5.0 Other Study Materials5.0 Other Study Materials

Document DescriptionDocument Description

• Bibliographic Bibliographic description of the description of the DDI document DDI document itself, otherwise itself, otherwise known as a known as a marked-up marked-up codebookcodebook

Study DescriptionStudy Description

• Describes Study or Describes Study or SurveySurvey

• Includes title, Includes title, abstract, keywords, abstract, keywords, author, publisher, author, publisher, collection methods, collection methods, etc.etc.

Data File DescriptionData File Description

• Contains Contains information information describing the data describing the data filefile

• Includes file name, Includes file name, file type, case file type, case quantity, logical quantity, logical record length, total record length, total number of records, number of records, etc. etc.

Variables DescriptionVariables Description

• Describes each Describes each variablevariable

• Includes variable Includes variable label, values, value label, values, value label, question, label, question, summary statistics, summary statistics, etc.etc.

Other Study MaterialsOther Study Materials

• Includes Includes documentation files documentation files in a variety of in a variety of formats: pdf, excel, formats: pdf, excel, word, etc.word, etc.

• Includes codebooks, Includes codebooks, questionnaires, user questionnaires, user guides, variability guides, variability tables, etc.tables, etc.

Choosing TagsChoosing Tags

• http://http://www.icpsr.umich.edu/DDI/users/dtd/cwww.icpsr.umich.edu/DDI/users/dtd/codedtd.htmlodedtd.html

• Select tags from each DTD section for Select tags from each DTD section for templatetemplate

• Each tag represents a searchable Each tag represents a searchable elementelement

• Choose carefully – definitions are Choose carefully – definitions are provided on-lineprovided on-line

Codebook TemplateCodebook Template

• Over 300 tags to Over 300 tags to choose fromchoose from

• DDI suggests DDI suggests starting with set of starting with set of Recommended Recommended ElementsElements

Making Templates - Making Templates - exampleexample

Marking up documentMarking up document

Tags can be filled by a variety of methods:Tags can be filled by a variety of methods:

• Cut and paste or type in information Cut and paste or type in information

• Extract information using custom scripts, Extract information using custom scripts, xml editors or custom softwarexml editors or custom software

• Follow tag descriptions carefullyFollow tag descriptions carefully

• Establish guidelinesEstablish guidelines

Completed CodebookCompleted Codebook

Your assignment…Your assignment…

To become familiar with the DDI To become familiar with the DDI structure and tagsstructure and tags

• Hands-onHands-on

• Using tried and true toolsUsing tried and true tools

• Assignment into groupsAssignment into groups

• Each group will mark-up one section of the Each group will mark-up one section of the DDIDDI

• Report back to the whole groupReport back to the whole group

Your working toolsYour working tools

• Pencil and paper templatePencil and paper template

• CCHS 1.1 documentationCCHS 1.1 documentation

• DDI tag libraryDDI tag library

• DDI schema (ascii representation)DDI schema (ascii representation)

• A few words about XMLA few words about XML

• Your colleaguesYour colleagues

Go to it!!Go to it!!

The endThe end

Carol Perry & Ernie BoykoCarol Perry & Ernie Boyko