Computer Packages ROCFIT Charles Metz and colleagues from the Department at Radiology, University of Chicago have created a computer program which does Maximum Likelihood Estimates... Read More

Signal Detection Theory (SDT) allows an analyst to separate sensitivity from response bias. Observers are assumed to make decisions based upon information derived from two... Read More

The receiver-operating characteristic (ROC) is a graphic representation of the relationship between the underlying Signal Absent and Signal Present distributions. This fundamental signal detection graphic... Read More

Criterion is a measure of the willingness of a respondent to say ‘Signal Present’ in an ambiguous situation. The choice of a criterion may depend... Read More

All of the measures used to describe performance in SDT are derived from the relationships between the Signal Present and Signal Absent distributions. d’ The... Read More

Before we continue, we should take a moment to review a few simple statistical transformations that are necessary for SDT calculations. In the model we... Read More

If we wish to compare memory ability for two people, why can’t we simply use the percent correct on identifying old items (i.e., hit rate)... Read More

The underlying model of SDT consists of two normal distributions, one representing a signal and another representing noise. In this tutorial, we refer to the... Read More

Reading in a coffee shop, you see someone who looks familiar. Have you met him before? A little while later you begin talking to someone... Read More