Contextsensitive

Context-sensitive, often written with a hyphen, describes phenomena whose interpretation or applicability depends on surrounding context. The term is used in linguistics, computer science, human-computer interaction, and information systems to indicate that meaning or behavior changes with context.

In linguistics, context-sensitive effects require nearby words or sounds to determine form or interpretation. Context-sensitive grammars (Type-1) permit production rules that depend on neighboring symbols, making them more powerful than context-free grammars. Phenomena such as morphophonemic alternations, agreement, and pronoun reference are commonly cited as context-sensitive.

In formal language theory, a context-sensitive grammar generates context-sensitive languages. Productions have the form αAβ → αγβ where A is a nonterminal and α, β, γ are strings of terminals and nonterminals, with γ nonempty and the overall length not decreasing. Languages produced in this way are recognizable by linear-bounded automata and are decidable.

In computing and human-computer interaction, context-sensitive behavior means software adapts to the current situation. Examples include context-sensitive help that offers guidance relevant to the active feature, and editors or IDEs that generate suggestions based on surrounding code or text.

Context-sensitive policies appear in security and information management, where access rules depend on context such as user identity, time, location, or system state, rather than solely on credentials.