Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

IREX VI: Mixed-effects Longitudinal Models for Iris Aging: Response to Bowyer and Ortiz



Patrick J. Grother, James R. Matey, George W. Quinn


Bowyer and Ortiz, in their paper “A Critical Examination of the IREX VI Results”, make seven criticisms of our application of linear mixed-effects models to longitudinally collected iris recognition Hamming Distances. We reject these as either irrelevant, misinterpretations or qualitatively correct but quantitatively irrelevant.
IET Biometrics


biometric aging, longitudinal analysis, iris recognition
Created November 20, 2015, Updated February 19, 2017