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.
Estimated item measures are plotted with their 95% CI (left), and estimated person measures are plotted with their standard errors (right), in d′ units. The data are color coded by 2-AFC (green) and 3-AFC (purple) and show that confidence intervals depend on the number of response alternatives.
