An earlier version of "Research Interests" as of 11/7/2008.

A fundamental working hypothesis in generative grammar is the existence of the language faculty, understood as an algorithm whose input is a set of items taken from the mental Lexicon of the speaker and whose output is a pair of mental representations - one underlying 'meaning' and the other 'sounds/signs'. The main goal of generative grammar can thus be understood as demonstrating the existence of such an algorithm and discovering its properties. Construed in this way, it is not language as an external 'object' but the language faculty that constitutes the object of inquiry. In the terms of the distinction made by Chomsky in the 1960s, generative grammar is concerned with competence rather than with performance.
　　　The data in actual research activities in generative grammar, however, is based on acceptability judgments on a given sentence, whether they are introspective judgments by the researchers or their informants or observation of various other types of reactions by 'subjects' in an experimental setting. I.e., what we deal with in an attempt to discover the properties of the speaker/hearer's competence (the Computational System) is his/her performance (i.e., language use, in a broad sense). This makes it crucial, in the context of generative grammatical inquiry as construed above, to articulate how we can extract from performance data evidence for a hypothesis about the properties of the Computational System. The absence of a minimally satisfactory articulation of how to do this is likely to lead to a situation where different (groups of) researchers base their proposals about the Computational System on different sets of speaker judgments, collected in a variety of ways, that are not necessarily uniform or robust, being subject to a great deal of fluctuation and variation not only among speakers but also within a single speaker. This makes it difficult to evaluate competing proposals in a reliable and objective manner. Recent debates in leading journals (e.g., Language, Lingua and Natural Language and Linguistic Theory) about what should qualify as data, about the use of introspective judgments as crucial evidence for or against a theory, etc. seem to suggest that we have not yet developed a means to evaluate the empirical bases of hypotheses in generative grammar that is compelling enough to the majority of the practitioners. An evaluation of a given hypothesis thus tends to have an arbitrary aspect to it, influenced by such factors as whether or not the terms and concepts utilized are of a theory currently in fashion and whether or not it endorses the standard view concerning the validity of alleged empirical generalizations, regardless of how much (or how little) 'repeatability' obtains in regard to the predicted speaker judgments on the crucial sentence forms.
　　　I have been working over the past decade to overcome the problem just noted, trying to articulate a concrete means to evaluate (not to arrive at) hypotheses in generative grammar, making specific reference to Japanese as its empirical basis for an illustration of the methodological points, which should be applicable to research on other languages, as long as it deals with interpretations that are claimed to be based crucially on properties of the Computational System.
　　　When one aims at discovering the properties of the language faculty as construed above, one must recognize the following: the Computational System's yielding something as its output does not guarantee that the speaker finds it (more precisely, finds its surface manifestation) to be acceptable; after all, non-grammatical as well as grammatical (i.e., the Computational-System-based) factors must contribute to the ultimate acceptability judgment by the speaker on a given sentence form under a specified interpretation (e.g., the memory limitation, familiarity with a particular sentence pattern, one's knowledge about the world, one's belief system, and the like, may be among the contributing factors). The Computational System's failure to yield something as its output, on the other hand, should necessarily mean that the 'sentence form' corresponding to such a 'failed representation' should be judged unacceptable under the specified interpretation. If something is predicted to be impossible due to the hypothesized formal properties of the Computational System under discussion, how can some pragmatic adjustment save it? Only by taking this point to heart and by putting forth a hypothesis so as to yield a negative prediction (the prediction that something is impossible (under a specified interpretation)), do we have a hope of making generative grammar an empirical science or of making it a progressive research program in the sense of Lakatos 1970.
　　　Properties of the Computational System can be best detected when we observe 'phenomena' where something has to be the way it is without any conceivable communicative or pragmatic reasons. And that is why researchers have focused on 'phenomena' of various forms of 'agreement' (e.g., he is sick … but not *he are sick) and cases where certain linguistic form must occur in some designated position in relation to other elements in the sentence in which it occurs (e.g., I wonder what John bought but not *I wonder John bought what). The forms prefixed by "*" are judged to be unacceptable by native speakers of English and their judgments are quite robust and uniform despite the fact that nothing seems to be terribly wrong with such forms from a communicative perspective – in fact when a non-native speaker makes such an utterance, the native speaker would most likely understand what is intended.
　　　If a language does not have what is responsible for such 'agreement' or 'obligatory (dis)placement of elements', as I assume/maintain is the case for Japanese, following Fukui 1986, we must look elsewhere in the language to find a reflection of the Computational System, and that is the area that has been called the interface between the language faculty and the faculty of mind that is responsible for interpreting the output of the Computational System. As briefly noted in [29940] in the Further Discussion board, the speakers' judgments (i.e., performance) is bound to be affected by factors that are independent of the Computational System, whether we consider their introspective judgments on the acceptability of a given sentence (under a specified interpretation) or some other form of their linguistic performance). Only by adopting the thesis that what the Computational System fails to give rise to never has the chance to be judged acceptable, can we have a hope of emerging out of the mud of this inherent difficulty with which we are faced, I maintain. Suppose we proceed to discover, on the basis of the hypothesis testing that has been suggested in Hoji 2006 and is currently being further developed and articulated, that some properties of Japanese are indeed due to the Computational System. We will have then learned that such properties are due to the Computational System but not due to what is responsible for 'agreement' or 'obligatory (dis)placement of elements'. It has been a rather common research practice in recent years to assume that all the properties that arguably stem from the Computational System are due to what is responsible for 'agreement' or 'obligatory (dis)placement of elements'. The general research program in which my 2007 Kyodai lectures (cf. the thread under [29940] in the Further Discussion board, which contains much of what is stated here) are embedded should therefore play a corrective function to such simple-minded approaches to the properties of the Computational System. Research on a language like English, where we seem to observe two types of reflections of the Computational System, is faced with an inherent difficulty in teasing the two apart. One might thus suggest that the general significance of research on a language like Japanese lies in the prospect of its providing new insight that is difficult to come by from research on a language like English.
　　　(1) has been demonstrated over the years. And I maintain (2).

(1)　　The Speaker judgments can converge as 'clearly unacceptable/impossible' under a specified interpretation on any instantiation of the schematic sentence form that is hypothesized to correspond to an impossible output of the Computational System.

(2)　　The research that aims to demonstrate the existence of, and discover the properties of, the Computational System (that is hypothesized to be at the core of the language faculty) must assign a special and central role to the sentence forms that have the property noted in (1), not only in the context of hypothesis testing but also in determining what 'phenomenon' most likely qualifies as an object of explanation, i.e., speaker intuitions as a reflection of the Computational System.

　　　(1) goes directly against a widely accepted (in a sense, pessimistic) view that we cannot expect to obtain a uniform or robust acceptability judgment since our judgment is affected by various factors of language use, the view that is based on the frequent observation that there is a great deal of variation and instability in speakers' acceptability judgments, especially when the sentence forms and the intended interpretations in question become complex and involved. The research that has led to (1), by myself and my students and colleagues, has made it clear that it is possible to obtain convergent judgments by proceeding in accordance with (2), even in 'areas' where judgmental variation and fluctuation have been notoriously common and pervasive.
　　　In summary, the major concerns underlying my research include (3).

(3) 　a. 　How can we try to ensure and measure progress in what we do in generative grammar?
　　　b. 　How can we tell whether or not given intuitions of ours are likely to be a reflection of properties of the Computational System?

　　　Not every observation qualifies as something that must be accounted for by a theory about the Computational System; it must first be demonstrated that it is most likely a reflection of properties of the Computational System. And, for the reasons briefly noted above and further elaborated elsewhere (e.g., Hoji 2006), to do so would require the recognition of the significance of negative predictions insofar as the research in question is aimed at demonstrating the existence of and discovering properties of the Computational System. This is the central methodological claim I am making and is the guiding thesis for the research projects I have been engaged in.

Lakatos, I. 1970. "Falsification and Methodology of Scientific Research Programmes," in I. Lakatos and A. Musgrave (eds.), Criticism and the Growth of Knowledge. Cambridge University Press. pp. 91-195.

For the specific research topics of mine and my students' and colleagues', please visit the "Downloadable Papers" page, the Discussion boards, and the "Works by other linguists" pages.