David A. Heiser, a regular contributor to EDSTAT-L, has a nice web page at that covers some of the numerical accuracy and computational problems inherent in many statistical functions in Microsoft Excel. He also lists a series of tests that you can apply to these functions to evaluate their performance. Another section of Dr. Heiser’s web page includes a list of the various measures of skewness and kurtosis. I only skimmed these resources, but they look quite good. www.daheiser.info