An EDDS is a SAS data set that provides information about the columns of a tall data set. It describes relevant experimental
variables
such as treatment conditions and
covariates
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 frequently constructed using information from a corresponding
experimental design file (EDF). An EDDS contains many of the same columns as an EDF, but, unlike the EDF, must be saved as a SAS data set (.
sas7bdat
). Many of the input engines that generate a tall data set from raw data files also automatically generate the needed EDDS.