KNN

CLASSIFICATION

AGENDA

o Feature Scaling o KNN CLASSIFICATION

KNN
Classification

What is Classification

o Motivation: Prediction
o Is a bank loan applicant "safe" or "risky"? o Which treatment is better for patient, "treatment X" or "treatment Y"?o Classification is a data analysis task where a model is constructed to
predict classlabels(categories)

The Basics General Approach

A two-step process:
cLearning (training)step a construct classification model
?Build classifier for a predetermined set of classes
?Learn from a training dataset (data tuples + their associated classes) a
Supervised Learning
cClassification step a model is used to predict class labels for given data
(testset)

The Basics General Approach

Training
data

Class
label

Attribute
vector

Classification
Algorithm

Classification
rules

The Basics General Approach

Test
data

(Mohammed, youth, medium)
Loan decision?Does it best fit the
first category, or the second?