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DDI for the Uninitiated. Ernie Boyko Statistics Canada Chuck Humphrey University of Alberta. ACCOLEDS /DLI Training: December 2003. Cataloguing Experiences. How many have catalogued using MARC Dublin Core. Cataloguing Experiences. Objectives of cataloguing Inventory control
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DDI for the Uninitiated Ernie BoykoStatistics Canada Chuck HumphreyUniversity of Alberta ACCOLEDS /DLI Training: December 2003
Cataloguing Experiences How many have catalogued using • MARC • Dublin Core
Cataloguing Experiences Objectives of cataloguing • Inventory control • Location tool • Access • Distribution
Enter DDI • Documentation in a standardized mark-up language • Data Documentation Initiative (DDI) http://www.icpsr.umich.edu/DDI/
An Example • American Public Opinion and U.S. Foreign Policy, 1994 http://www.icpsr.umich.edu/DDI/samples/index.html http://www.icpsr.umich.edu:8080/DDI/SAMPLES/06561.xml http://datalib.library.ualberta.ca/accoleds/workshops/index.html
XML-DDI Benefits • The display of data documentation through a variety of style sheets; • Input for further processing, such as creating statistical package command files, conducting advanced searches, comparing variables across data files, driving data extraction engines, etc.
Data Documentation • There is a need for comprehensive data documentation that allows easily • Finding variables • By subject groupings • By keywords, phrases or terms • By response categories (value labels) • Through linkages from the questionnaire
Data Documentation • There is a need for comprehensive data documentation that allows easily • Tracing variables back to their origins • To a question • To a response category for a multiple response item • To the variables from which it was computed for a derived variable.
Data Documentation • There is a need for comprehensive data documentation that allows easily • Understanding the corrections that must be made because of the sampling methodology
What’s next? Let’s assume we have <ddi> compliant files … so what’s next? What are the choices?
General Choices • Feed your own system (input from a structured file) • Look at systems using <ddi> files directly • Wait for SAS, SPSS, etc. to become XML enabled • Wait and see
Projects Using DDI • NESSTAR • Health Canada -- DAIS • SDA, Berkeley • ICPSR’s metadata • University of Minnesota • US Census Bureau • Harvard Virtual Data Center
Data users NESSTAR Central Server Data Producers Global Access, Local Support
Tools • Finding and sorting • Browsing • Analysing • Publishing • Text • Journal articles • User guides • Methodology instructions Hyperlinks • Data • Survey • Indicators • Administrative • Geographical • People • Email • Conferences • Experts • Discussion lists Data Observatory Workbench
Prepare your data using the Nesstar Publisher • Import data and metadata from a variety of formats • Cut and paste additional metadata from external sources • Use templates to enforce structure and local ”best practice” • Organize your variables in groups and sub-groups • Add local controlled vocabularies or thesauri • Validate your data/metadata against the DDI and your local ”best practice” • Output DDI-instances and/or publish to a Nesstar server Microdata in SPSS, SAS, Stata, Statistica, ascii or other formats Import Table- or aggregated data in Excel, Ascii or other formats Documentation/metadata in various text-formats, including XML Data or metadata sitting in relational databases Data Sharing - The NESSTAR Way (in 3 Steps)
Publish your data to a Nesstar server • Publish over the Web or a local area network (LAN) • Organize your data in folders and sub-folders • Define the access conditions of your data • Customize the user-interface to your data Publish Data Store Data Sharing - The NESSTAR Way (in 3 Steps) – (cont’d)
3. Share and explore your data through a variety of interfaces • Nesstar Explorer – a feature rich data browser (Java application) • Nesstar light – the standard web-browser interface to Nesstar resources and services • Choose between a variety of customized interfaces • Develop your own customized interface or integrate Nesstar services in an existing web-application Access Data Store Data Sharing - The NESSTAR Way (in 3 Steps) – (cont’d)
Demo • URL:http://nesstar1-4.essex.ac.uk/nesstarlight/
Where do we go from here? • Need to start producing <ddi> files • Need to create incentives for survey managers to create <ddi> files • Need to work cooperatively to convert legacy files