. What (Linguistic) Ambiguity Isn’t

‘Ambiguity’, as used by philosophers of language and linguists, refers to a different phenomenon from many closely related cases of multiple permissible interpretations. Distinguishing ambiguity from these related phenomenon can be a difficult and tendentious affair. We will discuss testing for ambiguity below: for now, we will try to isolate ambiguity by separating it from other typical cases with which ambiguity is easily conflated.

2.1 Vagueness

Characterizing vagueness is notoriously (and ironically) difficult, but it seems to stem from lack of precision in the meaning or reference of a term or phrase. There are clearly words that are ambiguous but not (obviously) vague: ‘bat’ is not vague but it is ambiguous. ‘Is bald’ looks to be vague but not ambiguous. It may be difficult to apply a predicate but that may well be the reflection of a vaguely specified meaning, not many precise meanings that the word is ambiguous between.
A general hallmark of vagueness is that it involves borderline cases: possible cases that are neither clearly in the extension of the vague term nor clearly not in its extension. An alternative characterization involves fuzzy boundaries rather than borderline cases (see Fara 2000, 47-48). Cases of ambiguity can be like this: one can imagine a sorites series involving something that is clearly a baseball bat at t1 that is changed particle by particle into a chiropteran with borderline cases of each mid-series, thus being a vague case of ‘bat’ in both senses. However, ambiguity need not be characterized by borderline cases nor by sorites-series susceptibility.
Interestingly, there are views regarding vague language that treat vagueness as at least akin to ambiguity. Braun and Sider (2007) treat sentences with vague terms as expressing multiple distinct propositions and supervaluationism treats vague terms as expressing multiple distinct semantic values. But the relevant notion of multiple expression seem different from paradigmatic ambiguity in that the semantic values are very closely aligned. If anything, one might think that these views treat vagueness as a sort of polysemy.

2.2 Context Sensitivity

Context sensitivity is (potential) variability in content due purely to changes in the context of utterance without a change in the convention of word usage. Thus, ‘I am hungry’ varies in content speaker to speaker because ‘I’ is context sensitive and shifts reference depending on who utters it. ‘I’, however, is not massively ambiguous. ‘Bank’ is ambiguous, not (at least, not obviously) context sensitive. Of course, knowledge of context may well help disambiguate an ambiguous utterance. Nonetheless, ambiguity is not characterized by interaction with (extra- linguistic) context but is a property of the meanings of the terms.

2.3 Under-specification and Generality

I have a sister in New York, a sister in Kingston and one in Toronto. If I tell you that I am going to visit one of my sisters, what I say underspecifies which sister I am going to see. This can be frustrating if you are trying to figure out where I am going. But this doesn’t make ‘I am going to visit one of my sisters’ ambiguous. Its meaning is clear. The sentence is ‘sense-general’; it fails to specify some detail without thereby being ambiguous with respect to that detail. In general, under- determination and generality may leave open many possibilities without being ambiguous between those possibilities. One more terminological note: in the cognitive linguistics literature (e.g. Dunbar 2001) it is common to treat what we call ‘sense generality’ as vagueness: a single lexeme with a unified meaning that is unspecified with respect to certain features.
Similarly, if I tell you that I am going to visit my aunt, I underspecify whether it is my mother’s sister or my father’s sister whom I am going to go visit. Nothing follows about the univocality or ambiguity of ‘aunt’. It simply means ‘aunt’ is true of things that are female siblings of your parent. By the same token, ‘human’ doesn’t make any demand on an object’s race in order to be part of its extension.
It is easy to mistake sense generality for ambiguity, as often the extension of a univocal term can break up into two or more distinct salient categories. The sentence ‘I ordered filet mignon’ doesn’t specify whether or not the filet was to be given to me cooked or raw, and this might make all the difference in the world. You will surely be annoyed and say ‘that’s not what I meant’ at a restaurant if the waiter brings the filet raw, but not so at the butcher shop. Often it is difficult to tell when the distinction in extension corresponds to an ambiguity in the meaning of the term. But difficulty in telling these apart in some cases should not lead us to abjure the distinction.

2.4 Sense and Reference Transfer

One difficult phenomenon to classify is transference of sense or reference (see Nunberg, Ward). When you say ‘I am parked on G St.’, you presumably manage to refer to the car rather than yourself. Similarly, ‘I am traditionally allowed a final supper’ said by a prisoner is not about himself (there are no traditions regarding him). The mechanics of reference transfer are mysterious, and the interaction of transferred terms with the syntax is a matter of some dispute.
Of course, sentences can have many of these properties at once. ‘My uncle wonders if I am parked where the bank begins’ is sense-general, ambiguous, context-sensitive, vague and it involves reference-transfer. Nonetheless, it is important to keep these properties apart as the semantic treatment we give each may vary wildly, the ways of testing for them may require highly specialized considerations and their source may well differ radically from phenomenon to phenomenon.

3. Types of Ambiguity

There are different sources and types of ambiguities. To explore these, however, we will need to adopt some terminology to make clear what sorts of phenomena we are looking at. Those familiar with some of the issues in current syntactic theory can skip until the next section.
Modern linguistic theory involves, in part, the study of syntax. The dominant strain of current syntactic theory takes the lexicon as primitive and studies the rule-governed derivation of syntactic forms, which are structures known as LFs (or, more misleadingly, Logical Forms). The relationship of sentences in natural language to LFs can be one to many: the phonological/orthographic forms of a sentence can be associated with more than one LF. Thus, ‘every man loves a woman’ has been argued (e.g., May 1977) to involve two distinct logical forms.
A standard, but controversial, assumption is that LFs are the input to semantic theory, not the phonological/orthographic objects we hear and see. (see May 1985). Thus, while LFs are not ambiguous (syntactically), the sentences we actually use and assert often are. If this assumption turns out to be false, then it will be a great deal more difficult to locate the source of some ambiguities.
LFs can be thought of as trees, and the terminal nodes of the branches are taken from the lexicon. A lexicon is a repository of lexical items, which need not look like words and they certainly need not correspond to our intuitions about words. Thus, intuitions about a word’s modal profile suggest that it can undergo massive shifts in its orthographic and phonetic properties. It is far less clear that the lexemes retain their identity over shifts of phonological properties. We should be a bit careful, then, about the relationship between words and lexemes: a word may retain its identity while the lexeme it is derived from may not constitute it over time. Fortunately, issues of concerning the diachronic identity of words won’t concern us much here.
The LF driven picture of semantic interpretation is controversial for many reasons: some people don’t think that LFs are properly thought of as inputs to anything, never mind semantic interpretation. Cullicover and Jackendoff (2005) argue for much less extensive syntactic structures coupled with very messy mappings to semantic (or ‘conceptual’) structures. Others think that most of the work done by LFs could be done by taking a notion of surface syntax seriously, not positing hidden structure, and running very complicated semantic theories to account for the data. (Bittner 2007, Jacobson 1999). Thus, the description of some of the ambiguities as syntactic or structural rather than semantic can be somewhat controversial. We will highlight some of these controversies where possible.
One more clarification: ambiguity is a property of either sentences or perhaps the speech acts in which the sentences are used. There is no guarantee that every utterance of an ambiguous sentence will result in any unclarity regarding what was expressed or meant by the speaker. There is no guarantee that unambiguous utterances will result in full univocal clear understanding either. In some syntactic contexts, the ambiguity won’t show up at all: ‘I want to see you duck’ is a case in which the NP interpretation of ‘duck’ is simply unavailable (except in the case where we add a comma after ‘you’. In many cases our best theory predicts an ambiguity despite the fact that no reasonable person would detect any meaning other than the clearly intended one.

3.1 Lexical Ambiguity

The lexicon contains entries that are homophonous, or even co-spelled, but differ in meanings and even syntactic categories. ‘Duck’ is both a verb and a noun as is ‘cover’. ‘Bat’ is a noun with two different meanings and a verb with at least one meaning. ‘Kick the bucket’ is arguably ambiguous between one meaning involving dying and one meaning involving application of foot to bucket.
This sort of ambiguity is often very easy to detect by simple linguistic reflection, especially when the meanings are wildly distinct such as in the case of ‘bat’. It can be more difficult, however, when the meanings are closely related. A classic case is the short word ‘in’. The meaning(s) of ‘in’, if it is ambiguous, seem to revolve around containment, but at a more fine-grained level, the types of containment can seem wildly distinct. One can be in therapy, in Florida, in the Mafia, in the yearbook…but it seems like a joke to say that one is in therapy and the Mafia.
The considerations suggest that ‘in’ is ambiguous, but perhaps it is univocal with a very sense general meaning that involves containment of an appropriate sort and different objects require different sorts of appropriate containment. Telling between these two possibilities is difficult. An even harder case of lexical ambiguity involves the putative ambiguity in ‘any’ between the reading as a universal quantifier and a ‘free choice’ item. (see Dayal 2004)
A few points about lexical ambiguity should be kept in mind. First, a bookkeeping issue: should we relegate lexical ambiguity to the lexicon (two non-identical entries for ambiguous terms) or to semantic interpretation (one lexical entry, two or more meanings)? Second, the word/lexical item distinction may cause us some trouble. While ‘holey’ and ‘holy’ are homophonous, they are not co-spelled. Thus an utterance of ‘the temple is holey’ is ambiguous between two sentences, while an inscription in English is not. Sometimes co-spelled words are distinct sounding, such as ‘refuse’ which is distinct sounding (in my dialect at least) between ‘ree-fuze’ and ‘reh-fuse’. Fortunately, we have the relevant categories to describe these differences and we can talk about ambiguity in sound or in notation (or in sign).

. What (Linguistic) Ambiguity Isn’t

2.1 Vagueness

2.2 Context Sensitivity

2.3 Under-specification and Generality

2.4 Sense and Reference Transfer

3. Types of Ambiguity

3.1 Lexical Ambiguity

. What (Linguistic) Ambiguity Isn’t :: تعاليق

. What (Linguistic) Ambiguity Isn’t