Ambiguity
Ambiguity is a state in which the meaning of a phrase, statement, situation, or resolution is not explicitly defined, making for several plausible interpretations. It arises when available information lacks sufficient context or a shared frame, so people cannot reliably determine what the problem is, what matters, what causes what, or what solution would count as correct. As a result, interpretation depends heavily on prior experience, assumptions, and imagination.
An outcome of ambiguity is uncertainty, but uncertainty itself refers to a state in which outcomes or meanings are known but their likelihood, stability, or implications cannot be reliably assessed. Ambiguity is not simply the absence of information. It is the lack of meaning and direction caused by insufficient context and unclear framing, which obstructs the ability to determine what counts as a valid interpretation or resolution. The prefix ambi- reflects the idea of “two” or “multiple,” as in multiple possible meanings.
The concept of ambiguity is generally contrasted with vagueness. In ambiguity, multiple distinct interpretations compete because the frame of meaning is unclear and is shaped by personal history and mental models. With vagueness, in contrast, the general interpretation is often understood, but the boundaries are fuzzy, so it is difficult to specify the meaning at the desired level of precision.
Linguistic forms
Lexical ambiguity is contrasted with semantic ambiguity. The former represents a choice between a finite number of known and meaningful context-dependent interpretations. The latter represents a choice between any number of possible interpretations, none of which may have a standard agreed-upon meaning. This form of ambiguity is closely related to vagueness.Ambiguity in human language is argued to reflect principles of efficient communication. Languages that communicate efficiently will avoid sending information that is redundant with information provided in the context. This can be shown mathematically to result in a system that is ambiguous when context is neglected. In this way, ambiguity is viewed as a generally useful feature of a linguistic system.
Linguistic ambiguity can be a problem in law, because the interpretation of written documents and oral agreements is often of paramount importance.
Lexical ambiguity
The lexical ambiguity of a word or phrase applies to it having more than one meaning in the language to which the word belongs. "Meaning" here refers to whatever should be represented by a good dictionary. For instance, the word "bank" has several distinct lexical definitions, including "financial institution" and "edge of a river". Or consider "apothecary". One could say, "I bought herbs from the apothecary". This could mean one actually spoke to the apothecary or went to the apothecary.The context in which an ambiguous word is used often makes it clearer which of the meanings is intended. If, for instance, someone says, "I put $100 in the bank", most people would not think someone used a shovel to dig in the mud. However, some linguistic contexts do not provide sufficient information to make a used word clearer.
Lexical ambiguity can be addressed by algorithmic methods that automatically associate the appropriate meaning with a word in context, a task referred to as word-sense disambiguation.
The use of multi-defined words requires the author or speaker to clarify their context and sometimes elaborate on their specific intended meaning. The goal of clear, concise communication is that the receiver have no misunderstanding about what was meant to be conveyed. An exception to this could include a politician whose "weasel words" and obfuscation are necessary to gain support from multiple constituents with mutually exclusive conflicting desires from their candidate of choice. Ambiguity is a powerful tool of political science.
More problematic are words whose multiple meanings express closely related concepts. "Good", for example, can mean "useful" or "functional", "exemplary", "pleasing", "moral", "righteous", etc. "I have a good daughter" is not clear about which sense is intended. The various ways to apply prefixes and suffixes can also create ambiguity.
Semantic and syntactic ambiguity
occurs when a word, phrase, or sentence, taken out of context, has more than one interpretation. In "We saw her duck", the words "her duck" can refer either:- To the person's bird, or
- To a motion she made.
For the notion of, and theoretic results about, syntactic ambiguity in artificial, formal languages, see Ambiguous grammar.
Usually, semantic and syntactic ambiguity occur in the same sentence. The sentence "We saw her duck" is also syntactically ambiguous. Conversely, a sentence like "He ate the cookies on the couch" is also semantically ambiguous. Rarely, but occasionally, the different parsings of a syntactically ambiguous phrase result in the same meaning. For example, the command "Cook, cook!" can be parsed as "Cook, cook !", but also as "Cook, cook !" It is more common that a syntactically unambiguous phrase has a semantic ambiguity; for example, the lexical ambiguity in "Your boss is a funny man" is purely semantic, leading to the response "Funny ha-ha or funny peculiar?"
Spoken language can contain many more types of ambiguities that are called phonological ambiguities, where there is more than one way to compose a set of sounds into words, such as "ice cream" and "I scream". Such ambiguity is generally resolved according to the context. A mishearing of such, based on incorrectly resolved ambiguity, is called a mondegreen.
Philosophy
Philosophers spend a lot of time and effort searching for and removing ambiguity in arguments because it can lead to incorrect conclusions and can be used to deliberately conceal bad arguments. For example, a politician might say, "I oppose taxes which hinder economic growth", an example of a glittering generality. Some will think they oppose taxes in general because they hinder economic growth. Others may think they oppose only those taxes that they believe will hinder economic growth. In writing, the sentence can be rewritten to reduce possible misinterpretation, either by adding a comma after "taxes", or by changing "which" to "that", or by rewriting it in other ways. The devious politician hopes that each constituent will interpret the statement in the most desirable way, and think the politician supports everyone's opinion. However, the opposite can also be true—an opponent can turn a positive statement into a bad one if the speaker uses ambiguity. The logical fallacies of amphiboly and equivocation rely heavily on the use of ambiguous words and phrases.In continental philosophy, there is much greater tolerance of ambiguity, as it is generally seen as an integral part of the human condition. Martin Heidegger argued that the relation between the subject and object is ambiguous, as is the relation of mind and body and part and whole. In Heidegger's phenomenology, Dasein is always in a meaningful world, but there is always an underlying background for every instance of signification. Thus, although some things may be certain, they have little to do with Dasein's sense of care and existential anxiety, e.g., in the face of death. In calling his work Being and Nothingness an "essay in phenomenological ontology" Jean-Paul Sartre follows Heidegger in defining the human essence as ambiguous, or relating fundamentally to such ambiguity. Simone de Beauvoir tries to base an ethics on Heidegger's and Sartre's writings, where she highlights the need to grapple with ambiguity:
as long as there have been philosophers and they have thought, most of them have tried to mask it ... And the ethics which they have proposed to their disciples has always pursued the same goal. It has been a matter of eliminating the ambiguity by making oneself pure inwardness or pure externality, by escaping from the sensible world or being engulfed by it, by yielding to eternity or enclosing oneself in the pure moment.Ethics cannot be based on the authoritative certainty given by mathematics and logic, or prescribed directly from the empirical findings of science. She states: "Since we do not succeed in fleeing it, let us, therefore, try to look the truth in the face. Let us try to assume our fundamental ambiguity. It is in the knowledge of the genuine conditions of our life that we must draw our strength to live and our reason for acting".
Literature and rhetoric
In literature and rhetoric, ambiguity can be a useful tool. Groucho Marx's classic joke depends on a grammatical ambiguity for its humor, for example: "Last night I shot an elephant in my pajamas. How he got in my pajamas, I'll never know". Songs and poetry often rely on ambiguous words for artistic effect, as in the song title "Don't It Make My Brown Eyes Blue".In the narrative, ambiguity can be introduced in several ways: motive, plot, and character. F. Scott Fitzgerald uses the latter type of ambiguity with notable effect in his novel The Great Gatsby.