Context-sensitive rewrite rule

A more principled approach is to define a general rule format, a mle processor or engine and a clearly defined set of rules. This at least has the advantage of engine/rule separation meaning that the way the rules are processed and the rules themselves are separate, which helps with system maintenance, optimisation, modularity and e q)ansion to other languages. One common type of rule is the context-sensitive rewrite rule, which takes the form... 

Popular classifiers include context-sensitive rewrite rules, decision lists, decision trees, naive Bayes classifiers and HMM taggers. 

Most approaches use context sensitive rewrite rules of the type introduced in Section 5.2.4. Recall that these are of the form... 

The statistieal approach has been somewhat of a latecomer to grapheme-to-phoneme conversion, perhaps because of the success of other data driven techniques such as pronunciation by analogy or the impression that context-sensitive rewrite rules are adequate so long as they can be automatically trained, e.g. by a decision tree. In recent years however a number of approaches have been developed which give a properly statistical approach. 

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