What type of input fileset do you wish to use? The default is the standard text,
white-spaced-delimited (tab and/or space) PED and MAP fileset.
Alternatively, binary filesets are compressed to load faster and require
less disk space. (To create a binary fileset, select Create binary fileset in the Data Management
options on the next page.) In both cases, you can choose a phenotype from an alternate file.