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: