In the context of the Iris dataset, the feature that is most commonly used for distinguishing between the species based on petal measurements is the __________.

In the Iris dataset, the feature most often used to separate the species is petal length. This is because the different species have distinct petal lengths: setosa has short petals, while versicolor and virginica have progressively longer petals. By measuring petal length, a simple rule like “petal length > 5 cm” can already tell you whether a flower is setosa or not. For example, a flower with a petal length of 4. 5 cm is almost certainly setosa, whereas 6.