Feature structure

A feature structure is an abstract hierarchical structure that is used to represent linguistic properties and dependencies. Feature structures are used in some linguistic formalisms, such as the Head -driven Phrase Structure Grammar and lexical- functional grammar.

Feature structures consist of a set of pairs, each containing a feature name and an associated value. These values ​​, in turn, can have two different forms:

• You can be atomic, so do not be further disassembled and represent a single value.
• But they can also be complex. In this case, they are represented by a further sub- feature structure.

Feature structures are usually represented by attribute-value matrices. An example of a feature structure model, a person is shown here as an attribute - value matrix:

The person shown thus has the three features "Last Name ", " first name " and " address". The first two features are atomic, the last is complex and refers to a new feature structure that more accurately describes the address by specifying the " road ", " ZIP " and "place".

Can be compared with specific feature structures such as the subsumption relations with respect to their information content. In addition, they can be unified with each other. This means that the information contained in two feature structures are combined in a new feature structure. If the output structures, however, do not combinable information, then the unification fails.

Linguistically motivated unification

By means of unification is often depicted congruence in formal and applied linguistics. Since the unification is associative and commutative, one can easily deal with more complicated cases of congruence, such as doubled objects in Macedonian.

In block ја читам книгата " ( I ) read the book " congruent the proclitic pronoun in gender and number with the specific noun that is the direct object of the verb. Sowing the ( simplified ) feature structures of the individual words as follows

The following Unifizierungsschemata would create the syntactic structure of the sentence:

• P.case = acc & V.obj.gender = P.gender & V.obj.number = P.number & V.obj.def = true & V.objlc = P
• V.obj = N

If one were to interpret the above equations, for example, in Prolog, incur any syntax trees of the sentence. The objcl ( klitisches object) attribute is not linguistically motivated, but prevents two proclitic pronouns are appended for a direct object of the verb.

• Grammatical theory