Direct Compositionality

There is another debate, within the larger debate about compositionality, that has recently emerged and that debate concerns whether or not the principle involves a direct conception of compositionality. Direct compositionality pertains to a semantic analysis that requires that every constituent in a given expression receives a semantic value. This blocks various ways of underspecifying semantics such as Cooper Storage. These are typically strategies employed to delay the semantic analysis in an effort to resolve certain ambiguities or anaphoric and

scopal exigencies. But for a simple case of non-direct compositionality, consider the case of quantifier scope contrual in standard semantics:

a verb phrase such as saw everyone fails to have a semantic interpretation until it has been embedded within the large enough structure for the quantifier to raise and take scope (e.g. Someone saw everyone) (Barker and Jacobson, 2007: 2).

Generative linguistics assumes a level of logical form in which interpretation is conducted, this too is not directly compositional. The bottom-line is that in directly compositional accounts, every single constituent needs to have a semantic value even before introducing further context. The way in which this is achieved is through the strong requirement that for every syntactic operation there is a corresponding semantic operation. This means that every syntactically computed expression has a meaning, i.e. no distinct level of representation through which interpretation is conducted. Other (popular) ways of putting this is that the syntax and semantics operate in tandem.

There are two ways to look at direct compositionality. One way is to view it as a strengthening of the principle along the lines of the other proposals in the previous section. This is the less interesting view. The other way of viewing this version of compositionality is as the intended account of what is meant by compositional semantics.

The rationale for this interpretation of the principle is that it involves the simplest conception of grammar and that it contains actual insight into human sentence processing. The strategy for proving this is usually to shift the onus to those objecting to the direct interpretation. The first argument runs roughly as follows (courtesy of Jacobson (2012)):

1. Any theory of natural language should have a compositional syntax (a recursive proce- dure for proving the grammaticality of expressions)

2. Any theory of natural language should have a compositional semantics (a system for predicting the meaning of larger syntactic structures from smaller ones)

3. The simplest way to satisfy both (1) and (2) is a version of compositionality which makes the two systems work in tandem and not separately.

Of course, one could dispute whether either or both of the premises are valid but the real question is assuming these premises does (3) follow? The answer is no. It is very hard to employ Ockam’s Razor in the way that Jacobson wants to do so here, i.e. in abstacto. The matter is not as simple as comparing direct and indirect theories of compositionality. It has to be shown that in specific places where indirect methods are typically used for semantic analysis of phenomena, the same results can be achieved with direct analysis. Indeed, the motivation in most cases for indirect tactics is on a case by case basis. Thus, in certain cases the direct analysis might not be the simplest one. Therefore, I am not sure there is a legitimate application of simplicity considerations here. To illustrate this point, consider Montague Grammar. It contains ’Quantifying-In Rules’ and syntactic substitution rules for anaphoric reference, these are indirect methods of providing semantic values. Yet on the

whole, Montague Grammar is still considered to be directly compositional since there is a mapping between the syntactic and semantic rules ensuring that every expression has a meaning.

We can call any theory which relaxes the prohibition against reference to internal structure in the syntax a theory with “weak direct compositionality” (Barker and Jacobson, 2007: 4).

This gradation do not make for a very strong case for global strong direct compositionality. If we are allowed to “relax the prohibition” on internal structure in some cases then what stops us from creating a representational level in order to resolve various syntactic concerns which we encounter and interpret others directly.

The second reason advanced in favour of direct compositionality is that it better accounts for language-users tendency to parse sentences incrementally. Garden-path phenomena among other things lead us to believe that this is indeed the case, at least for the most part. This seems like a more compelling line than the previous one. Yet it doesn’t decide which brand of direct compositionality is best (Jacobson defines four) and the choice is non-arbitrary. Opting for one type as opposed to another could allow for more or less internal structures in the syntax (as we saw with Montague Grammar). In addition, levels of representation have been used in attempts at more cognitively realistic architectures for natural language processing and interpretation, consider Discourse Representation Theory. Nothing in the fact that human beings parse sentences incrementally necessitates that this process is done directly or compositionally for that matter.

At best, direct compositionality will be construed as a strengthening of the principle in its more common form with the amendment that a compositional semantics ought to be at least weakly directly compositional in some form.21