> Can any one suggest how to draw a ROC curve? I am trying

> to compare two digital systems used in dental radiology.

ROC curve fitting is described in the following papers:

Dorfman DD, Alf E. Maximum likelihood estimation of parameters of

signal detection theory and determination of confidence intervals

rating method data. J Math Psych 1969; 6: 487.

Dorfman DD, Berbaum KS, Metz CE, Lenth RV, Hanley JA, Dagga HA.

Proper ROC analysis: the bigamma model. Academic Radiol 1997; 4: 138.

Grey DR, Morgan BJT. Some aspects of ROC curve-fitting: normal and

logistic models. J Math Psych 1972; 9: 128.

Metz CE, Herman BA, Shen J-H. Maximum-likelihood estimation of ROC

curves from continuously-distributed data. Stat Med 1998; 17: 1033.

Metz CE, Pan X. "Proper" binormal ROC curves: theory and

maximum-likelihood estimation. J Math Psych 1999; 43: 1.

Swensson RG. Unified measurement of observer performance in detecting

and localizing target objects on images. Med Phys 1996; 23: 1709.

Any or all of our University of Chicago software for ROC analysis can be

downloaded without charge from

<http://www-radiology.uchicago.edu/sections/roc>. Most of these

programs are available in Windows, Macintosh and generic

UNIX/workstation/mainframe versions.

Charles Metz