In example 10.1 we introduced data from a CPAP machine. In brief, it's hard to tell exactly what's being recorded in the data set, but it seems to be related to the pattern of breathing. Measurements are taken five times a second, leading to on the o...
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This week is going to feel strange. "London 2012" will revert to simply being a reference to London in the year 2012 BC. Since the 2012 Olympics were awarded to London on 6th July 2005, the phrase "London 2012" has held special meaning and anticipati...
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Dynamite plots are a somewhat pejorative term for a graphical display where the height of a bar indicates the mean, and the vertical line on top of it represents the standard deviation (or standard error). These displays are commonly found in many scie...
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I am in countdown mode, in about a week I will be heading to SAS Global Forum 2012. As a SAS Instructor for over fourteen years, I have been to several conferences but never one in Orlando. I am excited for the busy forum that awaits. Sunday afternoon ...
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ODS Graphics have matured. With SAS 9.2, GTL and SG procedures were a new direction for creating analytical graphs in SAS. The motivation and design of the GTL framework and the SG procedures was driven primarily by the needs of the procedure writers...
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People here in the northeast US consider this to have been an unusually warm winter. Was it?The University of Dayton and the US Environmental Protection Agency maintain an archive of daily average temperatures that's reasonably current. In the case o...
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A colleague recently asked "why should the average get closer to the mean when we increase the sample size?" We should interpret this question as asking why the standard error of the mean gets smaller as n increases. The central limit theorem shows t...
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We often work in settings where the data set has a lot of missing data-- some missingness in the (many) covariates, some in the main exposure of interest, and still more in the outcome. (Nick describes this as "job security for statisticians").Some ana...
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