Why are data dimensions the keys to viewing data?

When you create a data set, you specify standard data dimensions, which indicate the additional information that will be saved when study data is collected.

Note: Clintrial users might find it helpful to compare specifying data dimensions to choosing a panel type. Data dimensions are similar to panel keys.

You can specify the following standard data dimensions when you create a data set.

Information in standard data dimensions

Standard data dimension	Information saved
Study	RefName of the study.
Subject	Subject ID.
Section	RefName of the section.
Section Index	Instance of a repeating section.
Event	RefName of the study event.
Event Index	Instance of a repeating study event.
Form	RefName of the form.
Form Index	Instance of a repeating form.
Item	RefName of the item.

You can also specify custom data dimensions. Like standard data dimensions, custom data dimensions specify additional information that is saved when study data is collected. You can provide names and values for custom data dimensions by selecting or creating a codelist, and you can allow a user-defined value. When you add an item to a data series contained by the data set, you are prompted to select a custom dimension label. You can choose a label from the list of codelist items, or, if providing a user-defined value is allowed, you can type a label name.

Note: In CIS data mapping definitions, custom dimensions are used to identify a subset key item for pages with multiple sections that contain the same panel items. The value of the subset key item determines the section in which data appears.