Bill Seymour has developed a new, more advanced Bayesian calculator for public use, and he would like people to beta test it and offer advice, or even develop it further.

For this open-source Bayes’ Theorem calculator, Seymour writes:

My intent was to find the middle way between, on the one hand, highly technical (and expensive) commercial software used in the sciences and statistics, and on the other hand, the toy Bayes’ Theorem calculators that abound on the Web. Some features of my calculator are:

• Hypotheses can be saved in permanent storage so that users can work on several at once as part of a larger project.
• Complete hypotheses can have any number of alternates.
• Priors and consequents can be almost any arithmetic expression that evaluates to a probability between 0 and 1.
• Prior and consequent expressions can contain terms that refer to other hypotheses.
• Probabilities can be entered, and displayed, as decimal numbers, percentages, or odds.
• The program happily works with what Carrier calls a fortiori probabilities: ranges of values like “20% to 40%”.

If you’re interested, here are some links:

• user documentation
• the current working model (beta)
• internal documentation (if you’d like to help, or if you’re just curious)

I’ve given the code the open-source Boost Software License which isn’t viral like the GPL and others are said to be; so if you’d like to use some of my ideas in a program of your own, the open-sourceness (if that’s a word) of my code won’t infect yours.

And I explicitly invite others to help with this project. In particular, I think it really should be a downloadable executable that can be run off-line. Unfortunately, writing GUIs isn’t in my wheelhouse (my failing, not GUIs’).

If anyone would like to create a Windows or OS X version; have at it. I’ll even host your source code on my Web site if it’s open-source and high-quality. (But be warned that I’m a professional programmer, and also an old fart, with some curmudgeonly ideas about how quality code should be written.) You’ll find my e-mail address at the end of the documentation.

So if you are interested, check that out. I have also added a link to these materials on my old calculator page so users have the option of both.