We frequently see much use of and commentary on the mean, medians, and modes of statistical distributions, as well as lengthy discussions of variance and skew (including the now famous “long tail“). But, what about fat tails? Is that a taboo subject? Maybe it is! For example, in the widely respected book Numerical Recipes: The Art of Scientific Computing, the authors had the audacity to say “the skewness (or third moment) and the kurtosis (or fourth moment) should be used with caution or, better yet, not at all.” Those warnings notwithstanding, kurtosis is making a comeback. Not that it ever went away, but a recent search on Google Scholar found over 3000 articles mentioning kurtosis in the context of statistics within the first three months of 2014, and over 12,000 articles in 2013, though only about 4000 such articles were cited in the preceding three years combined. Many of those contributions focus on real-world uses of that particular characteristic of data distributions.

So, what is kurtosis and what applications can we find for it in the Big Data world of Data Science?

(continue reading here … http://www.statisticsviews.com/details/feature/6047711/Kurtosis-Four-Momentous-Uses-for-the-Fourth-Moment-of-Statistical-Distributions.html)

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