The Use of Verb Information in Parsing: Different Statistical Analyses Lead to Contradictory Conclusions

The research investigated how comprehenders use verb information during syntactic parsing. Two reading experiments investigated the relationship between verb-specific variables and reading time. These experiments were close replications of prior work; however, two statistical techniques were used, rather than one. These were item-by-item correlations and participant-by-participant regression. In Experiment 1, reading time was measured using a self-paced moving window. In Experiment 2, eye movements were recorded during reading. The results of both experiments showed that the results of two types of statistical analyses support contradictory conclusions. The analyses involving participant-by-participant regression analyses provided no evidence for the early use of verb information in parsing and support syntax-first approaches to parsing. In contrast, the results of item-by-item correlation were consistent with the prior research, supporting the view that verb information can guide initial parsing decisions. Implications for theories of parsing are discussed. This research was financially supported by Grants HD-07327 and HD-18708 awarded to the University of Massachusetts at Amherst and supported by a grant awarded to the author by the National Science Foundation (BCS 0446998).     

汉语阅读中的心理词加工

通过两项研究考察了汉语阅读中心理词存在的心理现实性及其加工效率问题。研究1采用词切分任务考察语法知识掌握水平不同的读者词切分的差异,发现他们在词切分上存在很大分歧,语法知识越丰富,词切分差异越小。研究2探讨心理词的加工效率,使用阴影标记目标词,产生四种呈现条件：正常条件、词汇词条件、心理词条件和非词条件,结果发现心理词比词汇词、非词更容易加工。两项研究结果表明汉语阅读的基本信息单元更可能是心理词。     

Discourse influences during parsing are delayed.

Subjects read sentences containing either a syntactically ambiguous prepositional phrase attachment or a syntactically ambiguous reduced relative clause. The sentences were embedded in passages of text that were consistent with either the minimal or non-minimal attachment reading. In addition, a discourse factor (i.e., whether or not the target sentence was in the discourse focus) was varied. Subjects' eye movements were recorded as they read the passages of text. Our primary finding was that subjects were garden-pathed even when there was biasing context. However, when the target sentence was in the discourse focus, subjects were able to recover more readily from their initial erroneous parse of the sentence. The data thus support models of sentence parsing that postulate that the parsing of a sentence is based upon structurally based principles and the influence of semantic or pragmatic information makes itself felt only after the initial parsing decision has been made.     

Linguistic rhythm guides parsing decisions in written sentence comprehension

Various recent studies attest that reading involves creating an implicit prosodic representation of the written text which may systematically affect the resolution of syntactic ambiguities in sentence comprehension. Research up to now suggests that implicit prosody itself depends on a partial syntactic analysis of the text, raising the question of whether implicit prosody contributes to the parsing process, or whether it merely interprets the syntactic analysis. The present reading experiments examine the influence of stress-based linguistic rhythm on the resolution of local lexical-syntactic ambiguities in German. Both speech production data from unprepared oral reading and eye-tracking results from silent reading demonstrate that readers favor syntactic analyses that allow for a prosodic representation in which stressed and unstressed syllables alternate rhythmically. The findings contribute evidence confirming immediate and guiding effects of linguistic rhythm on the earliest stages of syntactic parsing in reading.     

Memory mechanisms supporting syntactic comprehension

Efforts to characterize the memory system that supports sentence comprehension have historically drawn extensively on short-term memory as a source of mechanisms that might apply to sentences. The focus of these efforts has changed significantly in the past decade. As a result of changes in models of short-term working memory (ST-WM) and developments in models of sentence comprehension, the effort to relate entire components of an ST-WM system, such as those in the model developed by Baddeley (Nature Reviews Neuroscience 4: 829–839, 2003) to sentence comprehension has largely been replaced by an effort to relate more specific mechanisms found in modern models of ST-WM to memory processes that support one aspect of sentence comprehension—the assignment of syntactic structure (parsing) and its use in determining sentence meaning (interpretation) during sentence comprehension. In this article, we present the historical background to recent studies of the memory mechanisms that support parsing and interpretation and review recent research into this relation. We argue that the results of this research do not converge on a set of mechanisms derived from ST-WM that apply to parsing and interpretation. We argue that the memory mechanisms supporting parsing and interpretation have features that characterize another memory system that has been postulated to account for skilled performance—long-term working memory. We propose a model of the relation of different aspects of parsing and interpretation to ST-WM and long-term working memory.     

Parsing to Learn

Learning a language by parameter setting is almost certainly less onerous than composing a grammar from scratch. But recent computational modeling of how parameters are set has shown that it is not at all the simple mechanical process sometimes imagined. Sentences must be parsed to discover the properties that select between parameter values. But the sentences that drive learning cannot be parsed with the learner's current grammar. And there is not much point in parsing them with just one new grammar. They must apparently be parsed with all possible grammars, in order to find out which one is most successful at licensing the language. The research task is to reconcile this with the fact that the human sentence parsing mechanism, even in adults, has only very limited parallel parsing capacity. I have proposed that all possible grammars can be folded into one, if parameter values are fragments of sentential tree structures that the parser can make use of where necessary to assign a structure to an input sentence. However, the problem of capacity limitations remains. The combined grammar will afford multiple analyses for some sentences, too many to be computed on-line. I propose that the parser computes only one analysis per sentence but can detect ambiguity, and that the learner makes use of unambiguous input only. This provides secure information but relatively little of it, particularly at early stages of learning where few grammars have been excluded and ambiguity is rife. I consider three solutions: improving the parser's ability to extract unambiguous information from partially ambiguous sentences, assuming default parameter values to temporarily eliminate ambiguity, reconfiguring the parameters so that some are subordinate to others and do not present themselves to the learner until the others have been set. A more radical alternative is to give up the quest for error-free learning and permit parameters to be set without regard for whether the parser may have overlooked an alternative analysis of the sentence. If it can be assumed that the human parser keeps a running tally of the parameter values it has accessed, then the learner would do nothing other than parse sentences for comprehension, as adults do. The most useful parameter values would become more and more easily accessed; the noncontributors would drop out of the running. There would be no learning mechanism at all, over and above the parser. But how accurate this system would be remains to be established.     

Use of verb information in syntactic parsing: evidence from eye movements and word-by-word self-paced reading

We investigated whether readers use verb information to aid in their initial parsing of temporarily ambiguous sentences. In the first experiment, subjects' eye movements were recorded. In the second and third experiments, subjects read sentences by using a noncumulative and cumulative word-by-word self-paced paradigm, respectively. The results of the first two experiments supported Frazier and Rayner's (1982) garden-path model of sentence comprehension: Verb information did not influence the initial operation of the parser. The third experiment indicated that the cumulative version of the self-paced paradigm is not appropriate for studying on-line parsing. We conclude that verb information is not used by the parser to modify its initial parsing strategies, although it may be used to guide subsequent reanalysis.     

Produire et réviser la morphologie flexionnelle du nombre : de l'accès à une expertise

To understand how children and adults produce written text, you must first be able to describe how they acquire some basic mechanisms. This is the reason to study the acquisition and use of simple orthographic principles. Following this idea, the research of Largy, Fayol et al. concerns nominal and verbal agreement in French. This article proposes a synthesis of the recent development in this domain. Through the study of two competences to be acquired by the writer — (1) to produce the flexional morphology of number in written text and (2) to revise and judge the correctness of this production — this article presents and discusses in which way the learner access to a writing expertise, always relative.     

Two distinct parsing stages in nonword reading aloud: Evidence from Russian

Word reading partly depends on the activation of sublexical letter clusters. Previous research has studied which types of letter clusters have psychological saliency, but less is known about cognitive mechanisms of letter string parsing. Here, we take advantage of the high degree of context-dependency of the Russian orthography to examine whether consonant–vowel (CV) clusters are treated as units in two stages of sublexical processing. In two experiments using a nonword reading task, we use two orthogonal manipulations: (a) insertion of a visual disruptor (#) to assess whether CV clusters are kept intact during the early visual parsing stage, and (b) presence of context-dependent grapheme–phoneme correspondences (GPCs; e.g., л[а] → /l/; л[я] → /l^j/), to assess whether CV clusters remain intact or are split during the print-to-speech conversion stage. The results suggest that although CV clusters are initially processed as perceptual units in the early visual parsing stage, letters and not CV clusters drive print-to-speech conversion.     

Textual Appropriation in Engineering Master’s Theses: A Preliminary Study

In the thesis literature review, an engineering graduate student is expected to place original research in the context of previous work by other researchers. However, for some students, particularly those for whom English is a second language, the literature review may be a mixture of original writing and verbatim source text appropriated without quotations. Such problematic use of source material leaves students vulnerable to an accusation of plagiarism, which carries severe consequences. Is such textual appropriation common in engineering master’s writing? Furthermore, what, if anything, can be concluded when two texts have been found to have textual material in common? Do existing definitions of plagiarism provide a sufficient framework for determining if an instance of copying is transgressive or not? In a preliminary attempt to answer these questions, text strings from a random sample of 100 engineering master’s theses from the ProQuest Dissertations and Theses database were searched for appropriated verbatim source text using the Google search engine. The results suggest that textual borrowing may indeed be a common feature of the master’s engineering literature review, raising questions about the ability of graduate students to synthesize the literature. The study also illustrates the difficulties of making a determination of plagiarism based on simple textual similarity. A context-specific approach is recommended when dealing with any instance of apparent copying.     

The role of sublexical graphemic processing in reading

Dual-route models of reading postulate the existence of two separate mechanisms: The lexical route allows words to be recognized in their holistic form, and the sublexical route proceeds by converting the written sublexical entities of a word or a nonword into their corresponding phonological equivalents. Sublexical reading is assumed to require three stages of processing: graphemic parsing, graphophonemic conversion, and phoneme blending. This study provides evidence in favor of the existence of a graphemic parsing process which occurs prior to grapheme-phoneme conversion. A group of normal subjects read nonwords which contained multiletter graphemes significantly more slowly than graphemically simple nonwords. These results, best interpretable in the context of a recent dual-route model of reading, confirm previous data obtained in pathology which suggest the functional independence of this cognitive procedure.     

Lexical guidance in sentence processing: a note on Adams, Clifton, and Mitchell (1998)

Mitchell (1987) conducted a self-paced reading experiment that showed that people experienced difficulty reading a noun phrase when it immediately followed an intransitive verb. From this, he argued for a two-stage theory of parsing, in which verb subcategorization information is initially ignored. In response, Adams, Clifton, and Mitchell (1998) found no evidence to support this claim in an eye-tracking experiment and argued that Mitchell's segmentation procedure distorted the parsing process. We report an eye-tracking experiment, in which materials similar to those in Adams et al., but with longer noun phrases, were used, that showed a pattern of difficulty similar to Mitchell's findings. Hence, Mitchell's results did not depend on the use of an artificial method of presentation. The results cast further doubt on the adequacy of constraint-based accounts of parsing.     

Testing the shared resource assumption in theories of text processing

Eight experiments evaluated a core assumption of several theories of text processing, the shared resource assumption, which states that component text processes share limited processing resources. Short texts each contained two critical sentences that together warranted a causal inference. The syntactic structure of the second sentence was either more or less difficult to parse. Results from a lexical decision task suggested that readers formed the causal inferences when the syntactic structure was less difficult to parse but that inferencing was constrained when syntactic structure was more difficult. Follow-up experiments suggested that this interference was not due to inferior output of the syntactic parser nor to the increased demands of difficult syntax interfering with maintenance of information needed to form the inference. The results suggest insufficient resources were available for the operation of inference processes due to the increased demands of syntactic parsing, consistent with the shared resource assumption.     

Learning From Electronic Texts: Effects of Interactive Overviews for Information Access

This research investigated the effects of structured and unstructured overviews on learning from electronic text. It compared review strategies and text representations developed for traditional continuous text and for electronic text with a structured overview (a hierarchically organized map of the text content) and an unstructured overview (a menu-like content listing). Both overviews produced better memory for text topics and better breadth of recall compared with traditional text. However, when readers lacked specific study goals, the unstructured overview produced a more fragmented knowledge structure. This suggests that minimally structured overviews may be better for specific learning tasks than for gaining familiarity with new topics. The structured overview was easier for readers to recall and use. It also increased the amount of review when readers lacked specific study goals, suggesting that the overview design influences the extent to which readers take advantage of the flexibility provided by electronic text overviews.     

Children’s (in)ability to recover from garden paths in a verb-final language: Evidence for developing control in sentence processing

An eye-tracking study explored Korean-speaking adults’ and 4- and 5-year-olds’ ability to recover from misinterpretations of temporarily ambiguous phrases during spoken language comprehension. Eye movement and action data indicated that children, but not adults, had difficulty in recovering from these misinterpretations despite strong disambiguating evidence at the end of the sentence. These findings are notable for their striking similarities with findings from children parsing English; however, in those and other studies of English, children were found to be reluctant to use late-arriving syntactic evidence to override earlier verb-based cues to structure, whereas here Korean children were reluctant to use late-arriving verb-based cues to override earlier syntactic evidence. The findings implicate a general cross-linguistic pattern for parsing development in which late-developing cognitive control abilities mediate the recovery from so-called “garden path” sentences. Children’s limited cognitive control prevents them from inhibiting misinterpretations even when the disambiguating evidence comes from highly informative verb information.