Construction of Decision Tree for "Play Tennis?"

Values(Wind) = {weak, strong}

S = [9+, 5-]

S_weak = [6+, 2-]

= .811

S_strong = [3+, 3-]

= 1

Values(Outlook) = (rain, overcast, sunny)

S_rain = [3+, 2-]

=.971

S_overcast = [2+, 2-]

=0

S_sunny = [2+, 3-]

=.971

Gain(S, Temperature) = .029

Outlook has the highest Information Gain and thus classifies the root node.

[D1, D2, D8, D9, D11]

[2+, 3-]

S = .971

Gain(S_sunny, Temperature) = .570

Gain(S_sunny, Wind) = .570