@article{ref1,
title="Confidence, correctness, and difficulty with non-psychophysical comparative judgments",
journal="Perceptual and motor skills",
year="1963",
author="Nickerson, Raymond S. and Mcgoldrick, Charles C.",
volume="17",
number="1",
pages="159-167",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0031-5125",
doi="10.2466/pms.1963.17.1.159",
url="http://dx.doi.org/10.2466/pms.1963.17.1.159"
}