Editing Naive Bayes classifier (section)

====Training====
Example training set below.

{| class="wikitable"
|-
! Person !! height (feet) !! weight (lbs) !! foot size (inches)
|-
| male || 6 || 180 || 12
|-
| male || 5.92 (5'11") || 190 || 11
|-
| male || 5.58 (5'7") || 170 || 12
|-
| male || 5.92 (5'11") || 165 || 10
|-
| female || 5 || 100 || 6
|-
| female || 5.5 (5'6") || 150 || 8
|-
| female || 5.42 (5'5") || 130 || 7
|-
| female || 5.75 (5'9") || 150 || 9
|-
|}

The classifier created from the training set using a Gaussian distribution assumption would be (given variances are ''unbiased'' [[Variance#Population variance and sample variance|sample variances]]):
{| class="wikitable"
|-
! Person !! mean (height) !! variance (height) !! mean (weight) !! variance (weight) !! mean (foot size) !! variance (foot size)
|-
| male || 5.855 || 3.5033 × 10<sup>−2</sup> || 176.25 || 1.2292 × 10<sup>2</sup> || 11.25 || 9.1667 × 10<sup>−1</sup>
|-
| female || 5.4175 || 9.7225 × 10<sup>−2</sup> || 132.5 || 5.5833 × 10<sup>2</sup> || 7.5 || 1.6667
|}

The following example assumes equiprobable classes so that P(male)= P(female) = 0.5. This prior [[probability distribution]] might be based on prior knowledge of frequencies in the larger population or in the training set.