Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The DoF evaluation results from the usability survey. The error bars represent the standard error in the mean. Note that a rating of 5 corresponds to a DoF that is easy to control and 0 corresponds to a DoF that is very difficult to control.
