Nonlinear regression is an essential tool to analyze biological (and other) data. Many researchers use nonlinear regression more than any other statistical tool. Despite this popularity, there are few places to learn about nonlinear regression. Most introductory statistics books ignore nonlinear regression, and advanced statistics books exceed the mathematical sophistication of many scientists.

That's why GraphPad Software (developers of GraphPad Prism) created curvefit.com — an on-line resource center to help you learn about nonlinear regression, and its use in analyzing radioligand binding, dose-response, and enzyme kinetics data.

Much of the information on this site will be useful no matter what program you use for nonlinear regression. Prism is particularly easy to use, and it combines nonlinear regression with scientific graphics and statistics.

The following individuals made substantial contributions to the material in this site: Arthur Christopoulos (Pharmacology, Univ. Melbourne), Lee Limbird (Pharmacology, Vanderbilt Univ.), Richard Neubig (Pharmacology, Univ. Michigan), Paige Searle (Vice-president, GraphPad Software).

To cite material in this web site, I suggest this format:

Motulsky, H. J. (1999). Curvefit.com. The complete guide to nonlinear regression. Published by GraphPad Software. [Online]. Available: <http://www.curvefit.com>.

If you have any comments, suggestions or questions, please don't hesitate to email me.
Harvey Motulsky
President, GraphPad Software Inc.
hmotulsky@graphpad.com