Comments on: An SLD Marketing Puzzle http://www.blog.sethroberts.net/2007/07/08/an-sld-marketing-puzzle/ Self-Experimentation, Scientific Method, the Shangri-La Diet, etc. Fri, 09 Jan 2009 13:17:21 +0000 http://wordpress.org/?v=2.0.7 by: seth http://www.blog.sethroberts.net/2007/07/08/an-sld-marketing-puzzle/#comment-25396 Sun, 08 Jul 2007 17:49:21 +0000 http://www.blog.sethroberts.net/2007/07/08/an-sld-marketing-puzzle/#comment-25396 Yes, it is plotted on a log scale. When counts are plotted on square root or log scales, the variability is usually constant with changes in level -- one of the big reasons for the transformation. This data violates that expectation. If it were plotted on a "raw" (untransformed) scale, the reduction in variability would still be obvious because the pre-interview values cover such a wide range. Yes, it is plotted on a log scale. When counts are plotted on square root or log scales, the variability is usually constant with changes in level — one of the big reasons for the transformation. This data violates that expectation.

If it were plotted on a “raw” (untransformed) scale, the reduction in variability would still be obvious because the pre-interview values cover such a wide range.

]]> by: Rich http://www.blog.sethroberts.net/2007/07/08/an-sld-marketing-puzzle/#comment-25390 Sun, 08 Jul 2007 17:36:44 +0000 http://www.blog.sethroberts.net/2007/07/08/an-sld-marketing-puzzle/#comment-25390 It looks like you have this plotted on some sort of log scale. If you take it off that scale, my guess is there isn't much decrease in variability. It looks like you have this plotted on some sort of log scale. If you take it off that scale, my guess is there isn’t much decrease in variability.

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