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.
Overall impact of differential item functioning (DIF) for gender and age on the test characteristic curves (TCC). The first (A) and third (C) plots display the TCC of all items and the second (B) and fourth (D) plots display the TCC of specific DIF items (i.e., item #10 for gender and item #21 for age).
