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 distress test is shown in left cluster of bars, the reading test, in the middle cluster, and the distress and reading tests are combined in the right cluster. Error bars show standard errors.
