Identify the median line inside the box
Read the lower edge of the box as the first quartile
Read the upper edge of the box as the third quartile
Use the box to see the interquartile range
Check the whiskers for the spread outside the middle 50%
Look for outliers shown as separate points
Compare median position within the box for skewness
Compare whisker lengths for asymmetry
Compare boxplots by median, spread, and outliers
Use the axis scale to read actual values