University of Massachusetts Amherst ScholarWorks@UMass Amherst Masters Theses 1911 - February 2014 1985 The oler of context in resolving syntactic ambiguity. Fernanda Ferreira University of Massachusetts Amherst Follow this and additional works at: https://scholarworks.umass.edu/theses Ferreira, Fernanda, "The or le of context in resolving syntactic ambiguity." (1985). Masters Theses 1911 - February 2014. 2222. Retrieved from https://scholarworks.umass.edu/theses/2222 This thesis is brought to you for free and open access by ScholarWorks@UMass Amherst. It has been accepted for inclusion in Masters Theses 1911 - February 2014 by an authorized administrator of ScholarWorks@UMass Amherst. For more information, please contact [email protected]. THE ROLE OF CONTEXT IN RESOLVING SYNTACTIC AMBIGUITY A Thesis Presented By MARIA FERNANDA FERREIRA Submitted to the Graduate School of the University of Massachusetts in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE February 1985 Psychology THE ROLE OF CONTEXT IN RESOLVING SYNTACTIC AMBIGUITY A Thesis Presented By MARIA FERNANDA FERREIRA Approved as to style and content by: Department of Psychology To my mother and father iii ACKNOWLEDGEMENTS I would like to express my appreciation to my committee, Chuck Clifton, Keith Rayner and Lyn Frazier. I thank Keith Rayner for his time and helpful advice, for allowing me the use of his laboratory, and for teaching me some of the techniques of the lab. I thank Lyn Frazier for providing me with insightful suggestions and comments at all stages in the preparation of this thesis. And I thank the Chairperson of my committee, Chuck Clifton, who has not only been a wonderful advisor but a friend as well . His encouragement has been invaluable, and his friendship has helped to make even the tedious stages of preparing this thesis enjoyable. I would like to thank my other friends in the department, and especially Susan Duffy for her time and patience while I was learning how to use the eyetracker. Finally, I thank John Henderson for many helpful discussions of the issues raised in this thesis, and for his care and personal support. Iv ABSTRACT The Role of Context in Resolving Syntactic Ambiguity (February, 1985) Maria Fernanda Ferreira, B.A., University of Manitoba M.S., University of Massachusetts Directed by: Professor Charles E. Clifton, Jr. The research presented in this thesis was conducted in order to determine whether contextual information provided by the discourse in which a syntactically ambiguous sentence is embedded would affect the syntactic processing of that sentence. The target sentence either had a simple syntactic structure (minimal attachment) or a complex one (nonminimal attachment). In Experiment 1, minimal attachment and nonminimal attachment sentences were placed in either appropriately biasing or neutral contexts, and subjects' reading times and question-answering accuracy were recorded. The results suggested that context did not affect the syntactic processor's initial analysis of the target sentences. The parser initially computes a minimal attachment structure, revising it only if the parser is presented with syntactically disambiguating information. The second Experiment experiment was conducted in order to extend the results of additional target 1. Both the materials from the first experiment and ambiguity were sentences which involved a different type of syntactic v 1 tested, and subjects eye movements were recorded. The results of the second experiment replicated the first and indicated that the processes of syntactic analysis and reanalysis are not affected by contextual information. These results are viewed as supporting an autonomous rather than an interactive model of language processing, in which modules or specialized processors operate independently and communicate in a highly constrained fashion. vi TABLE OF CONTENTS Acknowledgements iv Abstract v List of Tables ix List of Figures x Chapter X« INTRODUCTION 1 The Syntactic Processor 2 Autonomy and Interaction in Sentence Processing . 4 Information Sources in Sentence Comprehension . .11 Experiments 26 II. EXPERIMENT 1 30 Predictions 32 Method 33 Subjects 33 Materials 33 Procedure 36 Results 36 Discussion 44 III. EXPERIMENT 2 47 Method 53 Subjects 53 Apparatus 54 Materials 55 Procedure .... 58 Design 59 Results 61 First Pass Reading Times 62 Second Pass Reading Times 68 Regressive Eye Movements 71 1 Questions 7 * Discussion 76 First Pass Reading Time 76 Second Pass Reading Time 82 86 Regressive Eye Movements and Question- Answering . 87 Self-Paced Reading Time vs. Eye Movement Recording . Reduced Relatives vs. PP Attachment Ambiguities . 89 IV. GENERAL DISCUSSION 91 103 Discovering Structure Within the Language Processor. vii The Modularity of the Syntactic Processor . 106 REFERENCES 110 APPENDIX * \ \ \ A '. ! '. 114 B 129 c 130 D 151 vili LIST OF TABLES 1. Example of a passage in the four experimental conditions, Experiment 1 35 2. Mean reading times for each region in each condition, Experiment 1 37 3. Mean differences between obtained reading time and reading time expected on the basis of region length only, Experiment 1 41 4. Percentage correct for each condition, Experiment 1 .43 5. Example of a prepositional phrase passage in all four conditions, Experiment 2 56 6. Scoring regions of the target sentences, Experiment 2 • .60 7. Mean first pass reading times, Experiment 2 63 8. Mean second pass reading times, Experiment 2 69 9. Mean number regressions per target sentence for each condition, Experiment 2 75 10. Percentage correct for each condition, Experiment 2 . .77 ix LIST OF FIGURES 1. Mean reading time for each region in each condition, Experiment 1 . 38 2. Minimal attachment and nonminimal attachment structures for the prepositional phrase attachment ambiguity sentences, Experiment 2 51 3. First pass reading times for reduced relatives, Experiment 2 65 4. First pass reading times for double arguments, Experiment 2 66 5. First pass reading times for conjunction control, Experiment 2 67 6. Second pass reading times for reduced relatives, Experiment 2 70 7. Second pass reading times for double arguments, Experiment 2 72 8. Second pass reading times for conjunction control, Experiment 2 73 9. Minimal attachment and nonminimal attachment structures for the conjunction control sentences, Experiment 2 . .81 x CHAPTER I INTRODUCTION A great deal of current research on sentence comprehension is concerned with the issue of how different categories of information potentially available to the language processor are used. A central question is whether the human sentence parsing mechanism (the parser) can be influenced by nonsyntactic information sources, such as semantic, pragmatic, and discourse-contextual information, or whether the parser assigns syntactic structure independently. This thesis is based on the position that the language processor consists of a number of subprocessors, each with its own distinct properties, and that these subprocessors interact in a constrained fashion. From this perspective, the fact that people typically arrive at the most plausible reading of a sentence is considered the outcome of the language processor f s highly structured use of different information sources. Experimental investigation is thus directed at uncovering the timing of online processes occurring during sentence comprehension in order to determine the structure of the language processing system. The Syntactic Processor The operation of the sentence comprehension mechanism can be revealed 1 2 by observing how it behaves when it is confronted with syntactic ambiguity, i.e., with more than one potential analysis of a portion of a sentence (Frazier, 1978). Frazier outlines a number of ways the parser might cope with ambiguity. The parser might compute all possible analyses in parallel, and then reject all but the one that is correct (Crain & Steedman, 1984). This strategy would ensure that the parser always correctly structures the ambiguous material, but it is computationally costly. Another strategy the parser might use is to delay making a decision about the analysis until disambiguating information has been received (e.g., Marcus. 1980). This option would place a heavy burden on memory, since it would involve holding unstructured material in working memory. Furthermore, unless the ambiguous string is structured in some way, it is hard to see how the parser would recognize disambiguating information when it did arrive. A final possibility is that the parser selects only one analysis. This strategy would be efficient, but it would also mean that the parser might choose the wrong analysis and have to reanalyze the ambiguous material. There is substantial evidence that the parser computes only one analysis, the first analysis available (Frazier, 1978; Frazier & Rayner, 1982; Rayner. Carlson, & Frazier, 1983). Frazier (1978) strategy: proposed that the parser follows the minimal attachment Attach incoming material into the phrase-marker being constructed well-formedness using the fewest syntactic nodes consistent with the rules of the language. This strategy is efficient in terms of 3 computational and memory load: Only one analysis at a time is constructed, and all incoming material is structured as it is received. Frazier and Fodor (1978) argue that a minimal attachment analysis is more efficient than a nonminimal attachment analysis because the minimal attachment analysis requires the accessing of fewer phrase structure rules.