Sepal Length Research Articles

Discrimination Analysis in Medicine

THE technique of discrimination analysis between two groups was first suggested by Fisher (1936)l to distinguish between two species of iris flowers, setosa and versicolor. The data available in this instance were measurements (x i) of sepal length, sepal width, petal length and petal width from 50 flowers of each type. Fisher suggested the construction of a new variable y, which would be a linear combination of the measurements xi, such that the ratio of the difference between the mean values of y for the two species to its standard error would be maximised. For any other flower belonging to the one or the other species, the value of y would be calculated and the flower assigned to the species with the nearer mean value for y.