There are 3 ways to enter parameters:

1. "Experiment" page
2. "Assay" page
3. upload tab delimited parameter file

"Experiment"page is used to enter parameters which are the same for all the assays in this group.

"Assay" page helps to submit/edit parameter of an individual assay and it implies editing a certain parameter assay by assay, which may be time-consuming.

Parameter file is introduced for the bulk submission of the parameters that vary from assay to assay and therefore cannot be entered through the "Experiment" page.
The advantage of the parameter file is that should a user wish to do so, he/she can submit absolutely all metadata in one file for up to several hundred assays. The drawback is that it takes time to build this file (e.g. in Excel).