Bihistogram

http://www.itl.nist.gov/div898/handbook/eda/section3/bihistog.htm

The bihistogram is an EDA tool for assessing whether a before-versus-after engineering modification has caused a change in

  • location;
  • variation; Or
  • distribution.

It Is a graphical alternative To the two-sample t-test. The bihistogram can be more powerful than the t-test In that all Of the distributional features (location, scale, skewness, outliers) are evident on a single plot. It Is also based on the common And well-understood histogram.