[R] (no answer)

Frank E Harrell Jr f.harrell at vanderbilt.edu
Sat Apr 1 16:14:32 CEST 2006

I have never taken a statistics class nor read a statistics text, but
I am in dire need of help with a trivial data analysis problem for
which I need to write a report in two hours.  I have spent 10,000
hours of study in my field of expertise (high frequency noise-making
plant biology) but I've always thought that statistics is something
that can be mastered on short notice.

Briefly, I have an experiment in which a response variable is
repeatedly measured at 1-day intervals, except that after a plant
becomes sick, it is measured every three days.  We forgot to randomize
on one of the important variables (soil pH) and we forgot to measure
the soil pH.  Plants that begin to respond to treatment are harvested
and eaten (deep fried if they don't look so good), but we want to make
an inference about long-term responses.  In addition, we forgot to
measure the response on some of the days before the plant was
terminated.  Some baseline variables were not measured for some
plants, when some of the other variables looked OK.  The response
variable is only known to exceed a certain value in some cases, and in
others is only known to be less than a certain value.  The response
variable also has a great number of ties at zero, and has extreme high
outliers.  The variability of responses seems to depend on whether
there was missing variables for the plant.  And halfway through the
experiment we changed instrumentation and personnel.  All of these
problems seem trivial when compared to what I have to deal with every
day in measuring plant sounds, so I hope that someone can help me as
soon as possible.  I would appreciate receiving a few paragraphs of
description of the analysis that I can include in my report, and I
would like to receive R code to analyze the data no matter which
variables I collect.  I do value your time, so you will get my
everlasting thanks.

Note that I will be out of the office from 1:15pm to 1:25pm today.
This information should be valuable to many.

I. Ben Fuld
Technical University of Plant Kinetics
Slapout, Alabama

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