Displays a dialog box that allows you to specify the plotting parameters for a box-and-whisker plot.
Select from "Median-based" or "mean-based".
The center point in a median-based display is the group median, or the middle value. If the number of items in a group is odd, the median is the exact value of the middle number. If the number of items in a group is even, the median is the average of the two middle values. The median is also known as the value at the 50th percentile.
The center point in a mean-based display is the group average.
The limits of the box are typically the 25th and 75th percentiles. The distance between them is also known as the IQR, or interquartile range. The box limits value is the range between the ends of the box, centered around the 50th percentile.
The whiskers typically represent the "non-outlier" minimum and maximum values within the group, though you have several options for defining these limits. Whiskers will never be drawn beyond the limits of the data, regardless of the "percentage" entry .
Limits function of:
Select from standard deviation or standard error (the standard deviation divided by the square root of the sample size). All plot limits are multipliers for this selection.
Limits expressed as % confidence
If limits are a function of standard error and this box is checked, then the limit input and legend display is expressed as a confidence level percentage, rather than a multiplier for the standard error. This option is meaningless (and disabled) if the limits are instead a function of standard deviation.
The limits of the box are typically the group standard deviation or the standard error.
The whiskers typically represent 2 or 3 standard deviations or standard errors.
For median-based plots, outliers are typically defined as those individual points which are greater than 1.5 times the IQR, beyond the end of the box. Uncheck this box if you do not wish to display outliers.
For mean-based plots, outliers are typically defined as those individual points which are greater than 2 or 3 standard deviations from the mean. They are typically not plotted when the box or whiskers represent standard errors.
For median-based plots, extremes are typically defined as those individual points which are 3 times the IQR, beyond the end of the box. Uncheck this box if you do not wish to display extremes.
Click this button to display the Box and Whisker Attributes dialog, where you may specify attributes for the box, whiskers, mean/median, outliers and extremes.