1) Introduction to the DDI (Hayley Mills, Hilde Orten, Anja Perry) This presentation will provide an introduction to the metadata standard DDI with focus on the work products of the DDI Alliance. It will include an overview of the background of DDI, who is using the standard, and for what purpose. 2) Study and variable description with DDI (Hayley Mills) The DDI standard allows the documentation of metadata from the high level of a study or project, to the lower level of an individual variable. This presentation will; i) describe how DDI represents these, ii) give the advantages of documenting metadata in this way, including for discovery and harmonisation; and iii) provide examples of where this has been achieved. 3) Questions and Instruments (Hilde Orten) The DDI contains detailed structures for describing individual survey questions as well as questionnaires. This presentation will; i) describe structures for documenting questions and instruments in DDI, ii) explore advantages for comparative surveys; and iii) provide examples of practical implementations based on DDI.