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.
Accuracy and reproducibility (precision) of a measurement. The true value is always an unknown but the closer the measurements mean get to it, the higher is the measurement accuracy. Source:http://en.wikipedia.org/wiki/File:Accuracy_and_precision.svg.
