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Re: st: RE: A modest proposal - missing data doesn't count

From   Phil Schumm <>
Subject   Re: st: RE: A modest proposal - missing data doesn't count
Date   Tue, 15 Jun 2010 13:05:49 -0500

On Jun 15, 2010, at 12:08 PM, Nick Cox wrote:
Paradoxical though it may seem, Allan has got to produce a stronger argument before it can judged exactly how good his proposal is.

Indeed. To quote Bill Gould ( ):

The last time we at StataCorp thought carefully about this problem, we learned that it is not enough to write down the statements for which the proposal better meets expectations. You have to go searching for the statements that do the unexpected and then ask, "How easy will that be to explain to users?"

I would suggest that there be some modest required reading here, to avoid wasting bandwidth. For example:

   (everything under the subject "My last word on a strange world")

2) an introduction to missing values in SAS (sorry -- this link may not work for everyone) documentation/cdl/en/lrcon/62955/HTML/default/a001292604.htm

3) an introduction to how NULL values are handled in SQL

Item (2) is useful for those who don't use SAS, since it demonstrates that SAS is similar to Stata in this regard, except with missing values stored at the bottom instead of at the top. Item (3) is useful for those who don't use SQL or are otherwise unfamiliar with multi- valued logic.

Others may be able to suggest additional references.

-- Phil

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