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United States Department of Agriculture

Agricultural Research Service



Probit analysis programs


We have developed programs for statistical analysis of data from bioassay studies. There is a program for analysis of serial time-mortality data. There are also accessory programs for transforming probit-transformed data back to proportion of test organisms responding to a stimulus, thus enabling graphing of observed and predicted data to assess goodness-of-fit of the probit line; a program for calculating relative potency of two lethal doses; and a program for determining whether slopes and intercepts from two probit equations are different.


Note: The programs were updated in June 2013 so that the programs will run in either Wolfram Mathematica 9 or Wolfram Player Pro.
Download time-mortality and accessory programs here


You may also download the program PriProbit that was developed by Dr. Masayuki Sakuma at Kyoto University in Japan. This program is for probit analysis of preference data, such as might be obtained in behavioral studies, but can also be used for analysis of dose-mortality data from bioassay studies. This program is supported by Dr. Sakuma, not USDA. USDA provides the program at this site only for the convenience of our customers. USDA does not guarantee the suitability of the program for data analysis. Questions about PriProbit and requests for support for PriProbit should be addressed to Dr. Sakuma at sakuma@kais.kyoto-u.ac.jp. The method upon which the program is based is described in:  Sakuma, M. 1998. Probit analysis of preference data. Appl. Entomol. Zool. 33: 339-347.
Download PriProbit program here.


Not sure which program you need? Click here.

Papers describing the techniques used:
 pdf icon PDF  Throne, J. E., Weaver, D. K., Chew, V., and Baker, J. E. 1995. Probit analysis of correlated data: Multiple observations over time at one concentration. J. Econ. Entomol. 88: 1510-1512.
 pdf icon PDF  Throne, J. E., Weaver, D. K., and Baker, J. E. 1995. Probit analysis: Assessing goodness-of-fit based on backtransformation and residuals. J. Econ. Entomol. 88: 1513-1516.



Last Modified: 2/24/2014
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