Note added in 2019: In modern seaborn versions the size argument has been renamed to height.

To be a little more concrete:

%matplotlib inline

import seaborn as sns

exercise = sns.load_dataset("exercise")

# Defaults are size=5, aspect=1
sns.factorplot("kind", "pulse", "diet", exercise, kind="point", size=2, aspect=1)
sns.factorplot("kind", "pulse", "diet", exercise, kind="point", size=4,