A knowledge of basic statistics is important for the researcher.
Chi-Square: A common analysis needed by the researcher is the comparison of two groups of data where the results can be categorized into only a few types of results. For example: Comparing the results of two different techniques of closing a tympanic membrane perforation. The results can be categorized into two types: Perforation closed or perforation not closed.
A Chi-Square test can be used to analyze this type of comparison:
For more about Chi-Square and a two-by-two online calculator go to
Two-by-two calculator with Fisher's Exact Test and Yates' Correction
For an online Chi-Square Calculator which uses up to nine rows and columns go to: http://www.physics.csbsju.edu/stats/contingency_
Download a two-by-two calculator
Other Online Chi-Square Calculators: