Nesstar enables data publishers to add information about their resources. For survey and tabular (cube) data the DDI metadata standard is recommended, and further information is given below.

For tabular (cube) data, item level metadata can also be added. This information is specific to one particular cell, or a range of cells, in a table and can be added using Nesstar Publisher.

What is the DDI?

The DDI (Data Documentation Initiative) is a metadata standard used for documenting datasets developed in European and North American data archives, libraries and official statistics agencies. It is designed to be machine readable, machine processable and compatible with the Dublin Core standard. To learn more about the DDI please visit the Data Documentation Initiative.

The following briefly describes some of the key sections of the DDI.

Document Description 

This section of a DDI-compliant document defines the bibliographic information that describes the document as a whole. This is similar to the information that a publisher might add to a book. It is also the section used to identify the manifestation of the underlying data and metadata file to electronic search facilities.

Study Description

The Study Description section includes all the naming and referencing information about the data that the DDI-compliant documentation file describes. This section typically includes information about the principal investigators, data distributors, dataset keywords, a summary (abstract) of the content of the data, data collection methods, geographic and temporal scope, and processing information.

File Description

The File Description section is made up of information about the particular data file(s) containing numeric and/or textual information that the DDI-compliant file describes. This section consists of items describing the characteristics and contents of the files that comprise the study as described in the Study Description. There may be multiple file descriptions if there are multiple files in the collection. This information is used by archival and dissemination systems, and some parts are completed automatically by the Nesstar Publisher. It is particularly useful to include version numbers and file names in this section.

Variable Description

The Variable Description section contains variable groups, if created, and individual variables within the data file that the DDI-compliant document describes. Variable groups may contain those variables that are related to a particular topic or section of a questionnaire. The Variable Description contains a comprehensive set of elements allowing for detailed descriptive information about response and analysis units, question text, interviewer instructions, universe, valid and invalid data ranges, and derived variables.

Other Materials

This section may include: questionnaires, coding information, software details and user manuals.