The shape of the data is often described by its symmetry or nonsymmetry
(also called skewness ).
Here are stem-and-leaf plots for *symmetric* , *right skewed*,
and *left-skewed* data.

SYMMETRIC DATA RIGHT-SKEWED DATA LEFT-SKEWED DATA 4 | 7 4 | 58 4 | 0 5 | 35 5 | 011245569 5 | 5 6 | 005 6 | 2445 6 | 2 7 | 11200 7 | 17 7 | 8 | 846799 8 | 8 | 17 9 | 0199 9 | 2 9 | 2445 10 | 41 10 | 5 10 | 011245569 11 | 1 11 | 0 11 | 58

The term `skew' refers to the direction of the longer tail if you stand the stem-and-leaf upright, or draw a histogram. Here is the histogram of the left-skewed stem plot above.

Histogram of left-skewed data

The long tail, of course, denotes outlying or
extreme observations.
The left-skewed histogram above
contains outlying *small* observations, while a right-skewed histogram
would have outlying *large* observations.
A left skew also indicates that the smallest quarter of observations will be more spread out.
See the boxplot below.

Boxplot of left-skewed data