Donated on 7/1/1988

A small classic dataset from Fisher, 1936. One of the earliest datasets used for evaluation of classification methodologies.

Dataset Characteristics


Subject Area

Life Science

Associated Tasks


Attribute Type


# Instances


# Attributes



Has the dataset been used for any tasks already?

Widely used for tasks such as classification and clustering, particularly for tutorial/teaching purposes

Additional Information

This is one of the best known datasets in statistics and machine learning. Fisher's paper is a classic in the field and is frequently used for tutorial and teaching purposes. The data set contains 3 classes of 50 instances each, where each class refers to a type of iris plant. One class is linearly separable from the other 2; the latter are not linearly separable from each other. Predicted attribute: class of iris plant. Attribute information: 1. sepal length in cm 2. sepal width in cm 3. petal length in cm 4. petal width in cm 5. class: -- Iris Setosa -- Iris Versicolour -- Iris Virginica This is an exceedingly simple domain. This data differs from the data presented in Fishers article (identified by Steve Chadwick, ). The 35th sample should be: 4.9,3.1,1.5,0.2,"Iris-setosa" where the error is in the fourth feature. The 38th sample: 4.9,3.6,1.4,0.1,"Iris-setosa" where the errors are in the second and third features. Each instance consists of measurements of an Iris flower


Attribute NameRoleTypeDescriptionUnitsMissing Values
sepal lengthFeatureContinuouscmfalse
sepal widthFeatureContinuouscmfalse
petal lengthFeatureContinuouscmfalse
petal widthFeatureContinuouscmfalse
classTargetCategoricalclass of iris plantfalse

1 to 10 of 5

Baseline Model Performance

351 citations




R.A. Fisher


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