Steps Natural Language Processing
- Suppose we have an English interface to an operating system and the following sentence typed: I want to print Bill’s .init file.
- The morphological analysis must do the following things:
- Pull apart the word “Bill’s” into proper noun “Bill” and the possessive suffix “’s”
- Recognize the sequence “.init” as a file extension that is functioning as an adjective in the sentence.
- This process will usually assign syntactic categories to all the words in the sentence.
- A syntactic analysis must exploit the results of the morphological analysis to build a structural description of the sentence.
- The goal of this process, called parsing, is to convert the flat list of words that form the sentence into a structure that defines the units that represented by that flat list.
- The important thing here is that a flat sentence has been converted into a hierarchical structure. And that the structure corresponds to meaning units when a semantic analysis performed.
- Reference markers (set of entities) shown in the parenthesis in the parse tree.
- Each one corresponds to some entity that has mentioned in the sentence.
- These reference markers are useful later since they provide a place in which to accumulate information about the entities as we get it.
- The semantic analysis must do two important things:
- It must map individual words into appropriate objects in the knowledge base or database.
- It must create the correct structures to correspond to the way the meanings of the individual words combine with each other.
- Specifically, we do not know whom the pronoun “I” or the proper noun “Bill” refers to.
- To pin down these references requires an appeal to a model of the current discourse context, from which we can learn that the current user is USER068 and that the only person named “Bill” about whom we could be talking is USER073.
- Once the correct referent for Bill known, we can also determine exactly which file referred to.
- The final step toward effective understanding is to decide what to do as a result.
- One possible thing to do to record what was said as a fact and done with it.
- For some sentences, a whose intended effect is clearly declarative, that is the precisely correct thing to do.
- But for other sentences, including this one, the intended effect is different.
- We can discover this intended effect by applying a set of rules that characterize cooperative dialogues.
- The final step in pragmatic processing to translate, from the knowledge-based representation to a command to be executed by the system.