An EDDS is a SAS data set that provides information about the columns of a tall data set. It describes relevant experimental
Variable
s such as treatment conditions and
Covariate
s as well as a variable named ColumnName. Entries in the ColumnName column must exactly match the column names in the input tall data set. EDDSs have certain constraints that must be followed for the processes to run successfully.
An EDDS is required by most processes using a tall input data set. Many of the input engines that generate a tall data set from raw data files also automatically generate the needed EDDS.