In general applications what applies to continuous data also applies to discrete data because continuous data is often discretized for usage and analysis. The instruction may not be 100% appropriate. I also know that chi-square goodness-of-fit can apply to discrete data also.

Thanks alot for your reply. But I am talking about the program itself. I have a data consists of 30 observations and I want to know is it fitting Poisson distribution or not. When I apply the easyfit, directly Kolmogorv-Smirnov and Anderson-Darling tests will be appeared without Chi-Square goodness of fit test. So, my problem is why the results of chi-square test do not appear as the other two tests?

This question should be addressed to the authors of the Easyfit software. The instructions and output could be to the best of their knowledge. Every software has its limitations.

Dear Delshad,

I agree with Ette. It is better to understand the right way to analyse your data rather than be overly concerned with the limitations of a particular software package.

Dear Peter, I agree with you two and even I did the analysis myself (chi-square test). I sent an email to easyfit too but till now did not answered me. I can't imagine that easyfit do a mistake, there should be a reason for their did or execution.