User Guide

566
Chapter 40
“missing” category to the set of markers. If there are no missing values, the
“missing” c
ategory is not displayed.
If you select this option and want to suppress display after the chart is drawn, select
the chart and then choose Properties from the Edit menu. Use the Categories tab to
move the cat
egories you want suppressedtotheExcludedlist.
This option is not available for an overlay scatterplot or for single-series charts in
which the data are summarized by separate variables.
Case Labels
Another option controls the status of case labels when a scatterplot is first displayed.
 Display chart with case labels. When this option is selected, all case labels are
displayed
when a scatterplot is created. By default, it is deselected—that is,
the default scatterplot is displayed without labels. If you select this option,
case labels may overlap.
Error Bars
If you are c
reating a categorical chart displaying means, medians, counts, or
percentages, another option is available:
 Display error bars. This option controls the display of error bars. For means,
you can ch
oose to display confidence intervals around category means, plus
and minus n times the variable standard deviation, or plus and minus n times
the standard error of the mean. For medians, counts, and percentages, only
confide
nce intervals are available.
All conf
idence intervals are individual intervals, with coverage levels (based on
the specified alpha) applying to individual categories, not the set of all categories
in the chart simultaneously. For counts and percentages, the intervals are based on
binomia
l intervals for the proportions of each category of the total over all categories,
appropriately rescaled to the count or percentage metric. Note that the confidence
intervals for counts, medians, and percentages are generally not symmetric around
the sta
tistic.