Stanford NLP note 48 -- using patterns to extract relations

The last section describes how to create an extractor, such as manual creation and machine learning. This section describes how to create a pattern manually. Citing what Professor jurafsky often says:

Let's look at the intuition.

Professor jurafsky always frowned and felt very cute.

The concept of the artificial model is very simple, for example: Like Xing ting, Xin Xue drop pills are a type of contraception.

If you are still young and do not know what xinsnow drop pills are, you will also know that xinsnow drop pills are a type of contraception after you see "XXX is a type of XXX. "Like XXX, it is also a pattern." For example, you know that xinsnow drop pills and Xing ting belong to the same thing.

Advantages and disadvantages of manual mode (plus and minus)

Advantages:

Industries with high accuracy and ability to customize certain characteristics

Disadvantages:

Low recall rate, trouble, think about these models to break your head

In the past, we used the manual pattern when we finally matched the pattern for License Plate Recognition. It was precise, complicated, and not universal.