On Thu, Dec 12, 2013 at 3:56 PM, Josh Berkus <j...@agliodbs.com> wrote:
> Estimated grouping should, however, affect MCVs.  In cases where we
> estimate that grouping levels are high, the expected % of observed
> values should be "discounted" somehow.  That is, with total random
> distribution you have a 1:1 ratio between observed frequency of a value
> and assumed frequency.  However, with highly grouped values, you might
> have a 2:1 ratio.

Cross validation can help there. But it's costly.

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