Psychology Dictionary of ArgumentsHome
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| Context, context dependency: sentences, words and texts depend to a varying extent on the addition of additional information to eliminate ambiguities. In particular, the use of index words such as "here", "now", but also of pronouns like "mine" leads to indeterminacy of the reference. The additional information may possibly be taken from an already existing information set, whereby the sentences to be examined, words or texts, form a subset of this more comprehensive set. Such a more comprehensive amount of information already existing elsewhere is called context. See also dependency, ambiguity, indeterminacy, discovery._____________Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments. | |||
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John Lyons on Context/Context Dependence - Dictionary of Arguments
I 229 Context-independent constituent structure grammar/linguistics/Lyons: until now, all constituent structure rules had the form A > B ("replace A by B") No matter the context. >Constituent structure grammar. Chomsky: studied the effects of organizing rules within the system, the consequences of introducing optional, alternative subrules and recursive rules. Conditions so far: 1. A and B must not be identical (i.e. A must not be replaced by itself), 2. A must be a simple symbol, B may be complex, which is usually the case. I 239 Context-dependent/Grammar/Lyons: Terminology: Context-dependent: context-sensitive, (c-dependent, c-restricted). Old: until now, all grammars we considered were context-independent. This means that the symbol to the left of the arrow in the output of the rule has been replaced by the symbol chain to the right. example N > N + and + N only condition: that N was in the input of the rule. E.g. alternative chains: (I) X + N + Y (II) W + N + Z then we get once X + N + and + N + Y W + N + and + N + Z Thus context-independent. (This was required!). I 239 Context-sensitive grammar/Chomsky: new: Instead of "Replace A with B": now: e.g. N > N + and + N/in the context X + ...+ Y I 241 Context-independent ones are special cases of dependent ones. New: Context Dependency: Assuming we have new rules: N > N + and + N/in the context X + ...+ Y Everyday language: "N is only to be replaced (optional or obligatory) if it is appears in the input chain... I 240 in such a way that X immediately follows on the left and Y immediately on the right. Then this rule would apply to (I) but not to (II). >Everyday language. Context-dependet rules: different types: (we limit ourselves to the options introduced so far: optional/obligatory, recursive/non-recursive, coordinated/subordinated): Variants: X and Y can represent one or more symbols. Assuming that the class of context-dependent grammars we are dealing with here is defined by the fact that in a rule of the type A > B/in the context X + ... + Y X and Y can (each individually) refer to any finite number of concatenated symbols, but that A must be a singular symbol. B must neither be identical to A nor zero. >Recursion. Then the following rules would be well-formed: a) P > Q/in the context E + F + ... + G b) P > Q + R/in the context E + ... + G + H + K + L c) P > R + S + T/in the context G +... + H etc. I 241 Context-independent grammar/Lyons: can be seen as a subclass of the (newly introduced) context-dependent grammars ((s) as special cases). Def Context-Independent/Lyons: if a rule has contextual variables X and Y with an unlimited value (i.e. they can be positive or zero), then the rule is context independent. Otherwise context-dependent. I 242 context-dependet: e.g. f) P > Q/in the context 0 (zero) + ... + 0 P may only be replaced by Q if there is no other sign to the left and right of P in the input chain. This normally only applies to the character . g) P > Q/in the context 0 (zero) + ... + R + S P may only be replaced by Q if the input chain is P + R + S. h) P > Q/in the context T + ... + 0 P may only be replaced by Q if it is at the last position in the input chain: T + P. General form with variables: X + A + Y > X + B + Y Then a context-free rule of the form A > B is a special case of a context-dependent rule in which there are no restrictions for the values of X and Y. Context-dependent and context-independent rules can be placed in the same formal framework. I 245 Congruence/Subject-verb-congruence/context-independent/Lyons: Example (1a) The dog bites the man (1b) The dog bites the men I 246 (1c) The dogs bite the man (1d) The dogs bite the men (2a) The chimpanzee eats the banana etc. Context-independent Grammar/Lyons: e.g. (1) ∑ > NP sing + VP sing or NP plur + VP plur. (2) VP sing > V sing + NP (3) VP plur > V plur + NP (4) NP > NP sing or NP plur (5) NP sing > T + N sing (6) NP plur > T + N plur (7) N sing > N + 0 (Null) (8) N plur > N + s (9) V sing > V + s (10) V plur > V + 0 Here, more than one symbol is replaced at a time. Lexical substitutions/Lyons: here we assume that their rules are outside grammar. >Lexicon, >Grammar. I 247 Number/context-independent grammar/Lyons: is defined here by rule (1) as the category of the sentence for the subject-verb congruence. However, it is also introduced in the object nominal expression by rule (4). Singular/Plural: so the alternative is something that is completely independent and different from the same alternative in the object position. The grammar does not make everything visible here, not even that the choice in subject and object position is independent, and that the verb, if the subject is once determined as singular or plural, is determined according to congruence. >Correctness. I 249 Context Dependence/Rules/Economy/Lyons: the rule growth to cover all other congruence ratios would be small. On the other hand, it would be significant in context-independent grammar. Here, context-dependent grammars are more economical. Correctness/lyons: both types of grammars formalize the congruence ratios correctly. I 250 Def Weak Adequacy/Grammar/Lyons: a grammar is weakly adequate when it generates the desired class of sentences. Def strongly adequate/Lyons: it is strongly adequate when it also assigns the correct structural description to each sentence. >Adequacy/Lyons. Correctness/Theory/Lyons: our definition of strong/weak adequacy implies in no way an interpretation of "correct". It does not even make an assumption as to whether there are any norms of "correctness". >Terminology/Lyons. However, we determine that it is possible, at least in certain cases, to say that one description is more correct than another. We just do not claim that we can decide what is "absolutely correct". Context-dependent/context-independent/grammar/adequacy/equivalence/Lyons: the two grammars are probably weak, but not strongly equivalent. The context-dependent is more appropriate. Comparability/equivalence/Lyons: since the two systems are weakly equivalent, they are at least comparable._____________Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution. Translations: Dictionary of Arguments The note [Concept/Author], [Author1]Vs[Author2] or [Author]Vs[term] resp. "problem:"/"solution:", "old:"/"new:" and "thesis:" is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition. |
Ly II John Lyons Semantics Cambridge, MA 1977 Lyons I John Lyons Introduction to Theoretical Lingustics, Cambridge/MA 1968 German Edition: Einführung in die moderne Linguistik München 1995 |
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> Counter arguments against Lyons
> Counter arguments in relation to Context/Context Dependence
