Hi, I'm not exactly sure what you are trying to say concerning the hypothesis. There is something called "weighting" when you are running statistics over a population. This is the way to correct the answers you received because you received too many answers from certain type of people This is a very well known process (I use to work in stastistics) but it requires initial population references (like number of men/women, number of people by age, by profession, etc..). This is too complex for the project as it usually requires a special algorithm running in special software. Most survey software don't do it themselves except that they allow to export the data so that you can calculate it in a separate tool and allow to load in your tool a "weight" for each response (this is a floating number close to 1). You then use this number to show your statistical result. Instead of doing Reponse 1 to question 1 : count(response 1) Reponse 2 to question 1 : count(response 2) You do Reponse 1 to question 1 : sum(weight * response 1) Reponse 2 to question 1 : sum(weight * response 2) Ludovic Chathura Prabuddha a écrit : -- Ludovic Dubost Blog: http://blog.ludovic.org/ XWiki: http://www.xwiki.com Skype: ldubost GTalk: ldubost