Investigators should plan to first describe their sample.
They should identify the important demographic characteristics
of the sample, such as sex, age, and race. These variables
will be the same for most studies. Other sample
characteristics, such as diagnosis, weight, height, Glasgow
Coma Scale, and so forth, also may be important to provide.
Descriptive statistics will describe these variables.
Next, investigators should plan the analyses for each
research question/hypothesis. A table may be useful for this
activity. In the first column should be the research question/hypothesis;
in the second, all relevant variables (and
timing information if needed); and in the third, the statistical
test to be used. This process helps investigators ensure
that they are collecting all needed data, at the right time, to
answer their question. After all study data have been collected
is not the time to discover that an important piece of
data has been missed