مؤلف القسم:Danielle J. Navarro and David R. Foxcroft
Descriptive statistics separately for each group
It is very commonly the case that you find yourself needing to look at
descriptive statistics broken down by some grouping variable . This is
pretty easy to do in jamovi. For instance, let’s say I want to look at the
descriptive statistics for some clinical trial data, broken down separately by
therapy
type. This is a new data set, one that you’ve never seen before.
The data is stored in the clinicaltrial
data set and we’ll use it a lot in
chapter Comparing several means (one-way ANOVA) (you can find a complete description of the
data at the start of that chapter). Let’s load it and see what we’ve got:
Evidently there were three drugs: a placebo, something called “anxifree” and
something called “joyzepam”, and there were 6 people administered each drug.
There were 9 people treated using cognitive behavioural therapy (CBT) and 9
people who received no psychological treatment. And we can see from looking
at the Descriptives
of the mood.gain
variable that most people did show
a mood gain (mean = 0.88), though without knowing what the scale is here it’s
hard to say much more than that. Still, that’s not too bad. Overall I feel that
I learned something from that.
We can also go ahead and look at some other descriptive statistics, and this
time separately for each type of therapy. In jamovi, check Std. deviation
,
Skewness
and Kurtosis
in the Statistics
options. At the same
time, transfer the therapy
variable into the Split by
box, and you
should get something like Fig. 18.
What if you have multiple grouping variables ? Suppose you want to
look at the average mood gain separately for all possible combinations of
drug
and therapy
. It is possible to do this by adding another variable,
drug
, into the Split by
box. Easy peasy, though sometimes if you
split too much there isn’t enough data in each breakdown combination to
make meaningful calculations. In this case jamovi tells you this by
stating something like NaN
or Inf
.[1]