The data supplied by a user during script execution is not directly persisted by IEG itself. This task is delegated to the Datastore (DS). The DS is a configurable database. Just as the questions and question pages that are to be displayed to the user are determined by an IEG script, the data that can be stored in the DS is dynamically determined by an XML schema. The schema describes the structure of the information you want to store and any relationships between the data. Data is stored in the DS in XML format and conforms to the W3C XML Schema Definition Language. More details on the DS and how it works can be found in the Creating Datastore Schemas guide.
An IEG script and a DS schema are very closely linked. An IEG script is defined with references to the elements contained in a schema and for that reason a schema must be supplied when editing a script. The same schema is also required when executing a script. Schemas may by reused to edit and execute multiple scripts so the same data structures can be used in different circumstances.