Just saw this old XKCD strip and came up with a more real-world-applicable, NLP version of the strip:

[ original image © Randall Munroe ]

For my non-NLP readers, I might as well explain the terms:

Wrapper Induction is “a technique for automatically constructing wrappers from labeled examples of a resource’s content.”. More details here .

CRF stands for Conditional Random Field and “is a type of discriminative probabilistic model most often used for the labeling or parsing of sequential data, such as natural language text or biological sequences.”