Simple Interactive Statistical Analysis

Free MS-DOS programs

The software presented here is for use on MSDOS computers. The procedures presented here have been developed a number of years ago and are the predecessors of the current SISA programs. The procedures are generally more powerful and much faster as the HTML/Javascript programs on the Website. Also, there are a number of procedures which are not available on the website. The general format is simple, if you type the procedure name only after the DOS prompt you get a short description of the procedure. Procedure name plus a number of parameters runs the program. Output is delivered on screen or on file, as you wish. Click procedure name to download program.

Poisson | Negative Binomial | Fisher | Multinomial
SPRT | CASRO | Partial Correlations | Chi-square

Software for calculating discrete distributions:

poisson

Calculates probabilities for samples which are very large in an even larger population. Is used to approximate the binomial distribution, try to compare it with the binomial!
The distribution is also, and more often, used in a completely different way, for the analysis of how rare events, such as accidents, cumulate for a single individual. For example, you can use it to estimate your chances of getting one, two, three or more accidents in any one year considering that on average people get 'U' accidents per year.

negative binomial

Another version of the negative binomial, this one is used to do the marginal distribution of binomials (try it!). Often used to predict the termination of real time events. An example is the probability of terminating listening to a non-answering phone after n-rings.

fisher

Is used to calculate the exact p-value in 2*2 tables. It is o.k. for one sided testing but not so exact for two sided testing, where there are different theories about how to do it. The sum of small p-values is the most used method, but there does not seem to be a good rationale for that. Use the fisher exact instead of the Chi-square when you have a small value in one cell or a very uneven marginal distribution.

Multinomial

The multinomial program is the exact solution to the Chi-square Goodness of fit test of testing for a difference between an observed and an expected distribution in a one-dimensional array. For example, the test can be used to compare the distribution of diseases in a certain locality with an expected distribution on the basis of national or international experiences using an ICD classification. In a two-category array the multinomial test provides a two-sided solution for the Binomial test. For example, Multinomial {10 20 0.20 0.80} gives the two-sided probability (0.105) for the single sided Binomial {0.20 10 30} probability (0.061). A flexible and powerfull Windows version of the Multinomial program is given away for free when you purchase the combined Tables and Distributions program..

Other Software

August, 1999. The T-test procedure and the Sample size procedure have been removed in the DOS/Pascal download version. Basically these procedures have not been maintained lately and the web versions are now much more extensive using better estimation

sequential probability ratio testing

This method of analysis is not often used, which is a pity because it is actually quite good. It is based on the case of phenomena being observed, tested, or data collected, sequentially in time. The testing or data collection is stopped as soon as some upper or lower limit is crossed of the proportion positive or negative events or outcomes relative to the total number observed. Was originally developed to keep the costs of 'destructive' testing low. Is sometimes used in medical trials to monitor the amount of negative side effects and to decide if the trial should be stopped because the number of side effect is considered unacceptably high.

CASRO

Calculates response rates according to different procedures. The CASRO (Council of American Survey Research Organizations) procedure is the 'accepted' procedure for surveys.

chi square (not available as interactive SISA procedure)

Calculates the Chi-square and some other measures for two dimensional tables

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