The term linguistic performance was used by Noam Chomsky in 1960 to describe “the actual use of language in concrete situations”. It is used to describe both the production, sometimes called parole, as well as the comprehension of language. Performance is defined in opposition to “competence“; the latter describes the mental knowledge that a speaker or listener has of language.
Part of the motivation for the distinction between performance and competence comes from speech errors: despite having a perfect understanding of the correct forms, a speaker of a language may unintentionally produce incorrect forms. This is because performance occurs in real situations, and so is subject to many non-linguistic influences. For example, distractions or memory limitations can affect lexical retrieval (Chomsky 1965:3), and give rise to errors in both production and perception. Such non-linguistic factors are completely independent of the actual knowledge of language, and establish that speakers’ knowledge of language (their competence) is distinct from their actual use of language (their performance).
Published in 1916, Ferdinand de Saussure‘s Course in General Linguistics describes language as “a system of signs that express ideas”. de Saussure describes two components of language: langue and parole. Langue consists of the structural relations that define a language, which includes grammar, syntax and phonology. Parole is the physical manifestation of signs; in particular the concrete manifestation of langue as speech or writing. While langue can be viewed strictly as a system of rules, it is not an absolute system such that parole must utterly conform to langue. Drawing an analogy to chess, de Saussure compares langue to the rules of chess that define how the game should be played, and parole to the individual choices of a player given the possible moves allowed within the system of rules.