Classification

Need of probabilistic predictions

We will denote the probability distribution over possible labels, given the input vector $x$ and training set $D$ by $p(y|x, D)$

Given a probabilistic output, we can always compute our best guess as to the true label using

$\hat{y} = \hat{f}(x) = argmax\space p(y = c|x, D)$

Real world applications

1. Email spam filtering
2. Image classification and handwriting recognition
3. Face detection and recognition