Java Reference
In-Depth Information
Extracting relationships
There are a number of techniques available to extract relationships. These can be grouped
as follows:
• Hand-built patterns
• Supervised methods
• Semi-supervised or unsupervised methods
◦ Bootstrapping methods
◦ Distant supervision methods
◦ Unsupervised methods
Hand-built models are used when we have no training data. This can occur with new busi-
ness domains or entirely new types of projects. These often require the use of rules. A rule
might be:
"If the word "actor" or "actress" is used and not the word "movie" or "commercial", then
the text should be classified as a play."
However, this approach takes a lot of effort and needs to be adjusted for the actual text in-
hand.
If only a little training data is amiable, then the Naive Bayes classifier is a good choice.
When more data is available, then techniques such as SVM, Regularized Logistic Regres-
sion, and Random forest can be used.
Although it is useful to understand these techniques in more detail, we will not cover them
here as our focus is on the use of these techniques.
