Abstract:
A method of grading an essay using an automated essay scoring system is provided. The method comprises the automated steps of (a) parsing the essay to produce parsed text, wherein the parsed text is a syntactic representation of the essay, (b) using the parsed text to create a vector of syntactic features derived from the essay, (c) using the parsed text to create a vector of rhetorical features derived from the essay, (d) creating a first score feature derived from the essay, (e) creating a second score feature derived from the essay, and (f) processing the vector of syntactic features, the vector of rhetorical features, the first score feature, and the second score feature to generate a score for the essay. The essay scoring system comprises a Syntactic Feature Analysis program which creates a vector of syntactic features of the electronic essay text, a Rhetorical Feature Analysis program which creates a vector of rhetorical features of the electronic essay text, an EssayContent program which creates a first Essay Score Feature, an ArgContent program which creates a second Essay Score Feature, and a scoring engine which generates a final score for the essay from the vector of syntactic features, the vector of rhetorical features, the first score feature, and the second score feature.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This Application is a continuation of U.S. Provisional Application Serial No. 09/120,427 filed Jul. 22, 1998, entitled ‘System and Method for Computer-Based Automatic Essay Scoring’, the contents of which are hereby incorporated by reference in their entirety. 
     This application is related to U.S. Provisional Patent Application Serial No. 60/053,375, filed Jul. 22, 1997, entitled “Computer Analysis of Essay Content for Automated Score Prediction,” the contents of which are hereby incorporated by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention generally relates to the field of computer-based test scoring systems, and more particularly, to automatic essay scoring systems. 
     BACKGROUND OF THE INVENTION 
     For many years, standardized tests have been administered to examinees for various reasons such as for educational testing or for evaluating particular skills. For instance, academic skills tests, e.g., SATs, LSATs, GMATs, etc., are typically administered to a large number of students. Results of these tests are used by colleges, universities and other educational institutions as a factor in determining whether an examinee should be admitted to study at that particular institution. Other standardized testing is carried out to determine whether or not an individual has attained a specified level of knowledge, or mastery, of a given subject. Such testing is referred to as mastery testing, e.g., achievement tests offered to students in a variety of subjects, and the results are used for college credit in such subjects. 
     Many of these standardized tests have essay sections. These essay portions of an exam typically require human graders to read the wholly unique essay answers. As one might expect, essay grading requires a significant number of work-hours, especially compared to machine-graded multiple choice questions. Essay questions, however, often provide a more well-rounded assessment of a particular test taker&#39;s abilities. It is, therefore, desirable to provide a computer-based automatic scoring system. 
     Typically, graders grade essays based on scoring rubrics, i.e., descriptions of essay quality or writing competency at each score level. For example, the scoring guide for a scoring range from 0 to 6 specifically states that a “6” essay “develops ideas cogently, organizes them logically, and connects them with clear transitions.” A human grader simply tries to evaluate the essay based on descriptions in the scoring rubric. This technique, however, is subjective and can lead to inconsistent results. It is, therefore, desirable to provide an automatic scoring system that is accurate, reliable and yields consistent results. 
     Literature in the field of discourse analysis points out that lexical (word) and structural (syntactic) features of discourse can be identified (Mann, William C. and Sandra A. Thompson (1988):  Rhetorical Structure Theory: Toward a functional theory of text organization, Text  8(3), 243-281) and represented in a machine, for computer-based analysis (Cohen, Robin:  A computational theory of the function of clue words in argument understanding,  in “Proceedings of 1984 International Computational Linguistics Conference.” California, 251-255 (1984); Hovy, Eduard, Julia Lavid, Elisabeth Maier, Vibhu Nettal and Cecile Paris:  Employing Knowledge Resources  in a  New Text Planner Architecture,  in “Aspects of Automated NL Generation,” Dale, Hony, Rosner and Stoch (Eds), Springer-Veriag Lecture Notes in Al no. 587, 57-72 (1992); Hirschberg, Julia and Diane Litman:  Empirical Studies on the Disambiguation of Cue Phrases,  in “Computational Linguistics” (1993), 501-530 (1993); and Vander Linden, Keith and James H. Martin:  Expressing Rhetorical Relations in Instructional , Text: A Case Study in Purpose Relation in “Computational Linguistics” 21(1), 29-57 (1995)). 
     Previous work in automated essay scoring, such as by Page, E. B. and N. Petersen:  The computer moves into essay grading: updating the ancient test.  Phi Delta Kappa; March, 561-565 (1995), reports that predicting essay scores using surface feature variables, e.g., the fourth root of the length of an essay, shows correlations as high as 0.78 between a single human rater (grader) score and machine-based scores for a set of PRAXIS essays. Using grammar checker variables in addition to word counts based on essay length yields up to 99% agreement between machine-based scores that match human rater scores within 1 point on a 6-point holistic rubric. These results using grammar checker variables have added value since grammar checker variables may have substantive information about writing competency that might reflect rubric criteria such as, essay is free from errors in mechanics, usage and sentence structure. 
     SUMMARY OF THE INVENTION 
     A method of grading an essay using an automated essay scoring system is provided. The method comprises the steps of (a) parsing the essay to produce parsed text, wherein the parsed text is a syntactic representation of the essay, (b) using the parsed text and discourse-based heuristics to create a vector of syntactic features derived from the essay, (c) using the parsed text to create a vector of rhetorical features derived from the essay, (d) creating a first score feature derived from the essay, (e) creating a second score feature derived from the essay, and (f) processing the vector of syntactic features, the vector of rhetorical features, the first score feature, and the second score feature to generate a score for the essay. 
     In a preferred embodiment, the method further comprises the step of (g) creating a predictive feature set for the test question, where the predictive feature set represents a model feature set for the test question covering a complete range of scores of a scoring guide for the test question, wherein in step (f), a scoring formula may be derived from the predictive feature set and the score for the essay may be assigned based on the scoring guide. Preferably, a batch of original essays, which are essays of a known score to a test question, are used in accordance with the model feature of the invention to create the predictive feature set. Creating the predictive feature set in this manner comprises the steps of repeating steps (a) through (f) for the batch of original essays and processing the vector of syntactic features, the vector of rhetorical features, the first score feature, and the second score feature for each original essay using a linear regression to generate the predictive feature set for the test question. 
     Preferably, each essay is already in the form of electronic essay text as in the case with on-line essay testing. If this is not the case, however, then the method of the present invention further comprises the step of converting the essay into the form of electronic essay text. 
     A computer-based automated essay scoring system for grading an essay also is provided. The essay scoring system comprises a Syntactic Feature Analysis program which creates a vector of syntactic features of the electronic essay text, a Rhetorical Feature Analysis program which creates a vector of rhetorical features of the electronic essay text, an EssayContent program which creates a first Essay Score Feature, an ArgContent program which creates a second Essay Score Feature, and a score generator which generates a final score for the essay from the vector of syntactic features, the vector of rhetorical features, the first score feature, and the second score feature. 
     In a preferred embodiment, the essay scoring system further comprising a parser for producing a syntactic representation of each essay for use by the Syntactic Feature Analysis program and the Rhetorical Feature Analysis program. In another preferred embodiment, the essay scoring system further comprising a Stepwise Linear Regression program which generates a predictive feature set representing a model feature set that is predictive of a range of scores for the test question which is provided to the scoring engine for use in assessing the final score for the essay. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The present invention will be better understood, and its numerous objects and advantages will become more apparent, by reference to the following detailed description of the invention when taken in conjunction with the following drawing, of which: 
     FIG. 1 is a functional flow diagram for a preferred embodiment of the e-rater system of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A computer-based system designed to automatically score essay responses is described herein. Solely for illustrative purposes, the following description of the invention focuses on the standardized GMAT Analytical Writing Assessments: (a)  Analysis of an Argument  (Argument essays) and (b)  Analysis of an Issue  (Issue essays) item types, examples of which are shown in Appendix A1 and Appendix A2, respectively. The system of the present invention, named e-rater as in Electronic Essay Rater, automatically analyzes several features of an essay and scores the essay based on the features of writing as specified in holistic scoring rubrics (descriptions of essay quality or writing competency at each score level of a 6-point scoring guide used by several standardized exams such as the GMAT, with 6 being the best score). 
     The present system automatically rates essays using features that reflect the 6-point holistic rubrics used by human raters to assign scores to essay responses. E-rater is completely automated so that it can be quickly moved into an operationally-ready mode and uses rubric-based features to evaluate essay responses, such as rhetorical structure, vocabulary and syntactic features. 
     E-rater uses a hybrid feature methodology. It incorporates several variables that are derived statistically, or extracted through Natural Language Processing (NLP) techniques. As described in this specification, e-rater uses four sets of critical feature variables to build the final linear regression model used for predicting scores, referred to as predictor variables. All predictor variables and counts of predictor variables are automatically generated by several independent computer programs. For argument and issue essay types, all relevant information about the variables are introduced into a stepwise linear regression in order to evaluate the predictive variables, i.e., the variables that account for most of the variation between essays at different score intervals. Variables included in e-rater&#39;s final score prediction model for argument and issue essays are: (a) structural features, (b) rhetorical structure analyses, (c) content vector analyses, and (d) content vector analyses by argument (argument vector analyses). A conceptual rationale and a description of how each variable is generated is described below. 
     A. Structural Features 
     The scoring guides for both argument and issue essays indicate that one feature used to rate an essay is “syntactic variety.” Syntactic structures in essays can be identified using NLP techniques. In the present invention, all sentences in the essay responses are parsed. The parser takes a sentence string as input and returns a syntactically analyzed version of a sentence, as illustrated in Table 1. Examination of syntactic structures in an essay response yields information about the “syntactic variety” in the essay. For example, information about what types of clauses or verb types can reveal information about “syntactic variety.” In Table 1, DEC is a declarative sentence, NP is a Noun phrase, AJP is an adjective phrase, ADJ is an adjective, NOUN is a noun, PP is a prepositional phrase, PREP is a preposition, INFCL is an infinitive clause, DETP is a determiner phrase, and CHAR is a character. 
     
       
         
               
             
               
             
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Syntactic Parse for a Sentence from an Issue Essay 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Young people often express discontent with taxation levels to support 
               
               
                 the aged. 
               
             
          
           
               
                 DEC1 
                 1NP1 
                 AJP1 
                 ADJ1* 
                 “Young” 
               
               
                   
                   
                   
                 NOUN1* 
                 “people” 
               
               
                   
                   
                 AVPI 
                 ADV1* 
                 “often” 
               
               
                   
                   
                   
                 VERB1* 
                 “express” 
               
               
                   
                   
                 NP2 
                 NOUN2* 
                 “discontent” 
               
               
                   
                 PP1 
                 PP2 
                 PREP1* 
                 “with” 
               
               
                   
                   
                 NP3 
                 NOUN3* 
                 “taxation” 
               
               
                   
                   
                   
                 NOUN4* 
                 “levels” 
               
               
                   
                 INFCL1 
                 INFTO1 
                 PREP2* 
                 “to” 
               
               
                   
                   
                   
                 VERB2* 
                 “support” 
               
               
                   
                 NP4 
                 DETP1 
                 ADJ2* 
                 “the” 
               
               
                   
                   
                   
                 NOUN5* 
                 “aged” 
               
               
                   
                   
                   
                 CHAR1 
                 “.” 
               
               
                   
               
             
          
         
       
     
     A program for examining syntactic structure was run on approximately 1,300 essays. The program counted the number of complement clauses, subordinate clauses, infinitive clauses, relative clauses and the subjunctive modal auxiliary verbs such as would, could, should, might and may, for each sentence in an essay. A linear regression analysis then selected the variables in Table 2 as predictive variables for the final score prediction model. By using these predictive variables, a vector of syntactic counts ( 42  in FIG. 1) for each essay is generated and is used by e-rater is the final scoring. 
     
       
         
               
             
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Grammatical Structural Variables Used 
               
               
                 in e-rater to Predict Essay Scores 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Argument Essays 
                 Total Number of Modal Auxiliary Verbs 
               
               
                   
                 Ratio of Complement Clauses Per Sentence 
               
               
                 Issue Essays 
                 Total Number of Infinitive Clauses 
               
               
                   
                 Total Number of Modal Auxiliary Verbs/Paragraph 
               
               
                   
               
             
          
         
       
     
     B. Rhetorical Structure Analysis 
     In both argument and issue essays, the scoring guides indicate that an essay will receive a score based on the examinee&#39;s demonstration of a well-developed essay. For the argument essay, the scoring guide states specifically that a “6” essay “develops ideas cogently, organizes them logically, and connects them with clear transitions.” For the issue essay, a “6” essay “develops a position on the issue with insightful reasons . . . ” and the essay “is clearly well-organized.” 
     Language in holistic scoring guides, such as “cogent”, “logical,” “insightful,” and “well-organized” have “fuzzy” meaning because they are based on imprecise observation. Methods of “fuzzy logic” can be used to automatically assign these kinds of “fuzzy” classifications to essays. This part of the present invention identifies the organization of an essay through automated analysis of the rhetorical (argument) structure of the essay. 
     The linguistic literature about rhetorical structure (Cohen (1984), Hovy et al. (1992), Hirschberg and Litman (1993), and Vander Linden and Martin (1995)) point out that rhetorical (or discourse) structure can be characterized by words, terms and syntactic structures. For instance, words and terms that provide “clues” about where a new argument starts, or how it is being developed are discussed in the literature as “clue words.” 
     Conjunctive relations from Quirk, Randolph, Sidney Greenbaum, Geoffrey Leech, and Jan Svartik:  A Comprehensive Grammar of the English Language,  Longman, New York (1985) including terms such as, “In summary” and “In conclusion,” are considered to be clue words and are classified as conjuncts used for summarizing. Clue words such as “perhaps,” and “possibly” are considered to be “belief” words used by a writer to express a belief in developing an argument in the essay. Words like “this” and “these” may often be used to flag that the writer has not changed topics (Sidner, Candace: 1986,  Focusing in the Comprehension of Definite Anaphora,  in “Readings in Natural Language Processing,” Barbara Grosz, Karen Sparck Jones, and Bonnie Lynn Webber (Eds.), Morgan Kaufmann Publishers, Los Altos, Calif., 363-394). It also was observed that in certain discourse contexts, structures such as infinitive clauses (INFCL) mark the beginning of a new argument, e.g., “To experimentally support their argument, Big Boards (INFCL) would have to do two things.” 
     One part of the present invention is an automated argument partitioning and annotation program (APA). APA outputs a file for each essay after it is partitioned into argument units. In addition, APA outputs a second file in which each sentence in an essay is annotated with word, term or structure classifications that denote argument structure. A specialized dictionary (lexicon) is used by APA to identify relevant clue words and terms. The lexicon used by e-rater is displayed in Appendix B1. 
     APA&#39;s heuristics select the dictionary-based clue words, terms, and non-lexical structures. Descriptions of the rules used by APA appear in Appendix B2. The rules that APA uses to partition and annotate arguments specify syntactic structure and the syntactic contexts in which clue words contribute to argument structure. APA uses parsed essays to identify syntactic structures in essays. Essays have been syntactically parsed and each sentence in the essay has a syntactic analysis. Table 3 illustrates original essay text and the text output by APA with corresponding argument partitioning annotations, where wording in the argument-unit annotations has been revised for comprehensibility. 
     
       
         
               
             
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Example of Automated Argument 
               
               
                 Partitions and Annotations (APA) 
               
             
          
           
               
                 Essay Text 
                 Argument Partitioned/Annotated Essay Text 
               
               
                   
               
               
                 “. . . Another problem with 
                   Another  problem with the argument is found 
               
               
                 the argument is found in 
                 in the evidence used to support it. 
               
               
                 the evidence used to 
                   
               
               
                 support it. Big Boards 
                 &gt;Start Argument at Parallel Word:  Another   
               
               
                 takes responsibility for 
                   
               
               
                 increasing River City&#39;s 
                 Big Boards takes responsibility for 
               
               
                 awareness of the marathon 
                 increasing River City&#39;s awareness of the 
               
               
                 runner over the three- 
                 marathon runner over the three-month 
               
               
                 month period by putting 
                 period by putting her name an billboards, 
               
               
                 her name on billboards, 
                 but they also stated that  there was   
               
               
                 but they also stated that 
                 
                   “extensive national publicity” of the 
                 
               
               
                 there was “extensive 
                 
                   woman during that time. 
                 
               
               
                 national publicity” of 
                   
               
               
                 the woman during that 
                 &gt;Argument Development at Contrast Word: 
               
               
                 time. The 30% increase 
                 
                   but 
                 
               
               
                 in awareness of this 
                 &gt;Argument Development at Complement 
               
               
                 woman could have been a 
                 Clause:  that . . .   
               
               
                 result of the national 
                   
               
               
                 publicity. Big Boards 
                 The 30% increase in awareness af this 
               
               
                 did not necessarily have 
                 woman  could  have been a result of the 
               
               
                 anything to do with River 
                 national publicity. 
               
               
                 City learning the woman&#39;s 
                   
               
               
                 name - they may have 
                 &gt;Speculation at Auxiliary Word:  could   
               
               
                 learned it from TV or 
                   
               
               
                 magazines or 
                 Big Boards did not necessarily have 
               
               
                 newspapers . . .” 
                 anything to do with River City learning 
               
               
                   
                 the woman&#39;s name - they  may  have learned 
               
               
                   
                 it. 
               
               
                   
               
             
          
         
       
     
     Table 4 shows the rhetorical variables used by e-rater for predicting scores. By using these predictive variables, a vector of rhetorical feature counts ( 54  in FIG. 1) for each essay is generated and used by e-rater in final scoring. 
     
       
         
               
             
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                 Rhetorical Structure Variables Used to Predict 
               
               
                 Scores for Issue and Argument Essays 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Argument Essays 
                  Total Occurrences of independent 
               
               
                   
                 Arguments in the Final Paragraph of the Essay 
               
               
                   
                  Total Occurrences of Subjunctive Modal Verbs 
               
               
                   
                 in the Final Paragraph of the Essay 
               
               
                   
                  Total Occurrences of Parallel Words that Begin 
               
               
                   
                 an Independent Argument 
               
               
                   
                  Total Occurrences of Argument Development 
               
               
                   
                 Using Belief Words 
               
               
                 Issue Essays 
                  Total Occurrences of Arguments Starting 
               
               
                   
                 With a Summary Phrase 
               
               
                   
                  Total Occurrences of Arguments Starting 
               
               
                   
                 With an Infinitive Clause 
               
               
                   
                  Total Occurrences of Arguments Starting 
               
               
                   
                 With a Subordinate Clause 
               
               
                   
                  Total Occurrences of Argument 
               
               
                   
                 Development Using an Infinitive Clause 
               
               
                   
                  Total Occurrences of Argument 
               
               
                   
                 Development Using a Belief Word 
               
               
                   
                  Total Number of Independent Arguments 
               
               
                   
                 in the Body of the Essay, Excluding The 
               
               
                   
                 First And Final Arguments/Paragraph 
               
               
                   
               
             
          
         
       
     
     C. Content Vector Analysis 
     The scoring rubric suggests that certain ideas are expected in an essay by stating that the essay “effectively supports the main points of the critique” for argument essays and “explores ideas and develops a position on the issue with insightful reasons and/or persuasive examples” for the issue essays. Content vector (CV) analysis is a statistical weighting technique used to identify relationships between words and documents. With regard to the approximate specifications in the rubric about essay content, CV analysis can be used to identify vocabulary (or content words) in essays that appear to contribute to essay score. 
     Assigning one of six scores to a GMAT essay is a standard type of classification problem. Statistical approaches to classification define each class (score) by the distribution of characteristics found in labeled training examples. Then, each test essay is analyzed, and its distribution is compared to that of the known classes. The class which best matches the test essay is selected. 
     For text, the characteristics may be physical (the number or length of words, sentences, paragraphs, or documents), lexical (the particular words that occur), syntactic (the form, complexity, or variety of constructions), rhetorical (the number or type of arguments), logical (the propositional structure of the sentences), or a combination of these. 
     Standard CV analysis characterizes each text document (essay) at the lexical (word) level. The document is transformed into a list of word-frequency pairs, where frequency is simply the number of times that the word appeared in the document. This list constitutes a vector which represents the lexical content of the document. Morphological analysis can optionally be used to combine the counts of inflectionally-related forms so that “walks,” “walked,” and “walking” all contribute to the frequency of their stem, “walk.” In this way, a degree of generalization is realized across morphological variants. To represent a whole class of documents, such as a score level for a set of essays, the documents in the class are concatenated and a single vector is generated to represent the class. 
     CV analysis refines this basic approach by assigning a weight to each word in the vector based on the word&#39;s salience. Salience is determined by the relative frequency of the word in the document (or class) and by the inverse of its frequency over all documents. For example, “the” may be very frequent in a given document, but its salience will be low because it appears in all documents. If the word “pterodactyl” appears even a few times in a document, it will likely have high salience because there are relatively few documents that contain this word. 
     A test essay is compared to a class by computing a cosine correlation between their weighted vectors. The cosine value is determined by the following equation: 
     
       
         cos=Σ( a   i   * b   i )/ sqrt (Σ( a   i   2 )*Σ( b   i   2 )) 
       
     
     where a i  is the frequency of word “i” in document “a” and b i  is the frequency of word “i” in document “b.” The larger the value of the correlation, the closer the test essay is to the class. The class which is closest to the test essay is selected and designated “Essay Score Feature A” ( 22  in FIG.  1 ). These steps are summarized below. 
     Vector construction for each document (or class): 
     Extract words from document (or combined documents) 
     Apply morphological analysis (optional) 
     Construct frequency vector 
     Assign weights to words to form weighted vector 
     Compute cosine correlation between test essay vector and the vector of each class 
     Select class with highest correlation 
     As discussed in the next section, CV analysis can also be applied to units of text smaller than essays. For example, it can be used to evaluate the rhetorical arguments within an essay. In this case, each argument is treated like a mini-document and is compared to the classes independently of the other arguments. The result is a vector of classes (scores), one for each argument in the essay. 
     E-rater uses a CV analysis computer program which automatically predicts scores for both argument and issue essays. The scores assigned by the CV analysis program are used as a predictor variable for the set of argument essays. 
     D. Argument-Content Vector Analysis 
     An important goal of this invention is to be able to predict essay scores based on “what the writer says.” CV analysis, as it is used above, identifies word associations over the essay as a whole. It looks at words randomly in the essay. Although this tells the reader something about possible essay content, it is important to capture words in a more structured way, so that topic may be identified using closely clustered word groupings. 
     The scoring rubric specifies that relevant essay content (or relevant words used in an essay) should be well organized and should address relevant content. Therefore, a revised version of the content vector analysis program was implemented and run on the “argument partitioned” training essays for argument and issue essays. 
     Another content similarity measure, ArgContent, is computed separately for each argument in the test essay and is based on the kind of term weighting used in information retrieval. For this purpose, the word frequency vectors for the six score categories, described above, are converted to vectors of word weights. The weight for word “i” in score category “s” is: 
     
       
           w   i,s =(freq i,s /max 13  freq s )*log( n _essays total   /n _essays i ) 
       
     
     where freq i,s  is the frequency of word “i” in category “s,” max_freq s  is the frequency of the most frequent word in category “s” (after a stop list of words has been removed), n_essays total  is the total number of training essays across all six categories, and n_essays i  is the number of training essays containing word “i.” 
     The first part of the weight formula represents the prominence of word “i” in the score category, and the second part is the log of the word&#39;s inverse document frequency (IDF). For each argument “a” in the test essay, a vector of word weights is also constructed. The weight for word “i” in argument “a” is: 
       W   i,a =(freq i,a /max_freq a )*log( n _essays total   /n _essays i ) 
     where freq i,a  is the frequency of word “i” in argument “a,” and max_freq a  is the frequency of the most frequency word in “a” (once again, after a stop list of words has been removed). Each argument (as it has been partitioned) is evaluated by computing cosine correlations between its weighted vector and those of the six score categories, and the most similar category is assigned to the argument. As a result of this analysis, e-rater has a set of scores (one per argument) for each test essay. The final score is then calculated as an adjusted mean of the set of scores, represented as ArgContent: 
     
       
         ArgContent=((arg_scores+ n _args)/( n _args+1) 
       
     
     This final score output is designated “Essay Score Feature B” ( 62  in FIG.  1 ). 
     E. The e-rater System Overview 
     FIG. 1 shows a functional flow diagram for a preferred embodiment of the e-rater system of the present invention. The first step in automatically scoring an essay is creating a model feature set, i.e., a model feature set used to predict scores at each score point of the scoring rubric. The system starts with a batch of approximately 250-300 original electronic essay text responses (essays already having a known score). Each original electronic essay text  10  is evaluated by EssayContent  20  to perform Content Vector Analysis (as described in Section C above) and to generate “Essay Score Feature A” and is also parsed by the parser 30 to produce a “syntactic” representation of each essay response, denoted as parsed essay text  32 . 
     Syntactic Feature Analysis  40  (program clause.c) then processes the parsed essay text  32  to extract syntactic information (as described above in Section A entitled “Structural Features”) and creates a vector of syntactic feature counts  42  for each syntatic feature considered by e-rater. Rhetorical Feature Analysis  50  (program gmat.c) also processes the parsed essay text 32 (as described above in Section B entitled “Rhetorical Structure Analysis”) to generate annotated text  52 , which includes a vector of rhetorical feature counts  54  and text partitioned into independent arguments  56 . This argument partitioned text  56  is then evaluated by ArgContent to perform Argument-Content Vector Analysis (Section D above) to produce “Essay Score Feature B”  62 . 
     The vector of syntactic features  42 , the vector of rhetorical features  54 , Essay Score Feature A  22 , and Essay Score Feature B  62  are then fed (depicted by the phantom arrows) into a stepwise linear regression  70 , from which a “weighted” predictive feature set  72  is generated for each test question using the batch of sample data. The set of weighted predictive features define the model feature set for each test question. 
     The steps just described above up to the linear regression  70  are then performed for a score to be predicted for each actual essay response. The vector of syntactic features  42 , the vector of rhetorical features  54 , Essay Score Feature A  22 , and Essay Score Feature B  62  for each response are then fed (depicted by the solid arrows) into the score calculation program  80  associated with the model answer for the test question with which the essay is associated and a Final Score 90 between 0 and 6 is generated. 
     It will be appreciated by those skilled in the art that the foregoing has set forth the presently preferred embodiment of the invention and an illustrative embodiment of the invention, but that numerous alternative embodiments are possible without departing from the novel teachings of the invention. All such modifications are intended to be included within the scope of the appended claims. 
     APPENDIX A1: ANALYSIS OF AN ARGUMENT ITEM 
     Analysis of an Argument Item 
     Time—30 Minutes 
     Directions: In this section you will be asked to write a critique of the argument presented below. You are not being asked to present your own views on the subject. 
     Read the argument and the instructions that follow it, and then make any notes in your test booklet that will help you plan your response. Begin writing your response on the separate answer document. Make sure that you use the answer document that goes with this writing task. 
     The following is from a campaign by Big Boards, Inc., to convince companies in River City that their sales will increase if they use Big Boards billboards for advertising their locally manufacted products. 
     
       
         
               
             
           
               
                   
               
             
             
               
                 “The potential of Big Boards to increase sales of your products can be 
               
               
                 seen from an experiment we conducted last year. 
               
               
                 We increased public awareness of the name of the current national 
               
               
                 women&#39;s marathon champion by publishing her picture and her name on 
               
               
                 billboards in River City for a period of three months. Before this time, 
               
               
                 although the champion had just won her title and was receiving extensive 
               
               
                 national publicity, only five percent of 15,000 randomly surveyed 
               
               
                 residents of River City could correctly name the champion when shown 
               
               
                 her picture; after the three-month advertising experiment, 35 percent of 
               
               
                 respondents from a second survey could supply her name.” 
               
               
                 Discuss how well reasoned you find this argument. In your discussion be 
               
               
                 sure to analyze the line of reasoning and the use of evidence in the 
               
               
                 argument. For example, you may need to consider what questionable 
               
               
                 assumptions underlie the thinking and what alternative explanations or 
               
               
                 counterexamples might weaken the conclusion. You can also discuss what 
               
               
                 sort of evidence would strengthen or refute the argument, what changes 
               
               
                 in the argument would make it more sound and persuasive, and what, if 
               
               
                 anything, would help you better evaluate its conclusion. 
               
               
                   
               
             
          
         
       
     
     Notes 
     Use the space below or on the facing page to plan your response. Any writing on these pages will not be evaluated. 
     Stop 
     You Finish Before Time is Called, You May Check Your Work on This Section Only. Do Not Turn to Any Other Section in the Test 
     APPENDIX A2: ANALYSIS OF AN ISSUE ITEM 
     Analysis of an Issue 
     Time—30 Minutes 
     Directions: In this section you will need to analyze the issue presented below and explain your views on it. The question has no “correct” answer. Instead, you should consider various perspectives as you develop your own position on the issue. 
     Read the statement and the instructions that follow it, and then make any notes in your test booklet that will help you plan your response. Begin writing your response on the separate answer document. Make sure that you use the answer document that goes with this writing task. 
     
       
         
               
             
           
               
                   
               
             
             
               
                 “Everywhere, it seems, there are clear and positive signs that people 
               
               
                 are becoming more respectful of one another&#39;s differences.” 
               
               
                 In your opinion, how accurate is the view expressed above? Use reasons 
               
               
                 and/or examples from your own experience, observations, or reading to 
               
               
                 develop your position. 
               
               
                   
               
             
          
         
       
     
     Notes 
     Use the space below or on the facing page to plan your response. Any writing on these pages will not be evaluated. 
     Stop 
     If You Finish Before Time is Called, You May Check Your Work on This Section Only. Do Not Turn to Any Other Section in the Test 
     
       
         
               
             
               
             
           
               
                   
               
               
                 Appendix B1: Lexicon (CLUELEX) used by e-rater 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 argument content#ALTERNATIVE::.or, either 
               
               
                  argument development class#BELIEF_word:: certainly, clearly, 
               
               
                  obviously, plainly, possibly, perhaps, potentially, probably, fortunately, 
               
               
                  generally, maybe, presumably, unless, albeit, luckily, unluckily, 
               
               
                  normally, for sure, apparently, herein, likely, surely, ideally, 
               
               
                  undoubtedly, naturally 
               
               
                 argument devlopment class#BELIEF_phrase:: for_certain, for_sure, 
               
               
                  of_course, to_some-extent, above_all, if only, in_order_to, 
               
               
                  in_order_for, so_that, so_as_to 
               
               
                 argument initialization class#CLAIM_N:: argument, 
               
               
                  arguments, assumption, assumptions, claim, claims, issue, issues; 
               
               
                  evidence, evidences, idea, ideas, flaw, flaws, study, stuidies, 
               
               
                  point, points, position, positions, leap_of_logic, conclusion, 
               
               
                  conclusions, emission, generalization, indication, indications, deduction, 
               
               
                  passage, factor, factors, problem, problems, statement, statements, 
               
               
                  discussion, discussions, question, questions, example, examples, 
               
               
                  counterexample, counterexamples, reason, reasons 
               
               
                 argument initialization class#CLAIM_phraseRO:: I, we 
               
               
                 argument initialization class#CLAIM THAT:: that 
               
               
                 argument development class#CONTRAST_word:: otherwise, conversely, 
               
               
                  however, nonetheless, though, yet, meanwhile, while, but, instead, 
               
               
                  although, still, notwithstanding, anyway, unlike 
               
               
                 argument development class#CONTRAST_phrase:: on_the_contrary, 
               
               
                  in_contrast, by_comparison, in_any_case, at_any_rate, 
               
               
                  in_spite_of, rather_than, on_the_other-hand, 
               
               
                  even_wordhen, even_if, even_though, even_wordith, 
               
               
                  apart_from, instead_of 
               
               
                 argument development class#DETAIL_word:: if, specifically, 
               
               
                  particutarly, when, namely 
               
               
                 argument development class#DETAIL_phrase:: for_example, 
               
               
                  for_instance, e.g, in_this_case, in_that_case, such_that, 
               
               
                  as_well_as, in-that, such_as, about_how, in_addition, 
               
               
                  in_addition_to 
               
               
                 argument development class#DISBELIEF_word:: unfortunately 
               
               
                 argument development class#EVIDENCE_word:: since, because, actually 
               
               
                 argument development class#EVIDENCE_phrase:: in_fact, after_all, 
               
               
                  as_a_matter_of_fact, because_of 
               
               
                 argument development class#INFERENCE_word:: accordingly, 
               
               
                  consequently, hence, thus, ultimately, so, thereby, then, therefore, 
               
               
                  following, after, afterward, afterwards 
               
               
                 argument development class#INFERENCE_phrase:: as_a_consequence, 
               
               
                  as_a_result, if_so, if_not, as_such, according_to, in_turn, 
               
               
                  right_after 
               
               
                 argument initialization class#PARALLEL_word:: firstly, essentially, 
               
               
                  additionally, first, second, another, third, secondly, thirdly, fourth, 
               
               
                  next, finally, final last, lastly, moreover, too, also, likewise, similarly, 
               
               
                  initially, further, furhermore 
               
               
                 argument initialization class#PARALLEL_phrase:: first_of all, 
               
               
                  in_the-first_place, for_one_thing, for_a_start, 
               
               
                  second_of_all, many_times, more_importantly, most_importantly 
               
               
                 argument development class#REFORMULATION word:: alternatively 
               
               
                 argument development class#REFORMULATION_phrase:: that_is, 
               
               
                  in_other words, i. e., briefly 
               
               
                 argument development class#RHETORICAL word:: ?, suppose, 
               
               
                  supposedly, supposing 
               
               
                 argument development class#RHETORICAL_phrase:: what if 
               
               
                 argument initialization class#SUMMARY_word: altogether, overall 
               
               
                 argument initialization class#SUMMARY_phrase:: all_in_all, 
               
               
                  in_conclusion, in_sum, in_summary, in_summation, in_short, 
               
               
                  on_the_whole 
               
               
                 arg auxiliary_verb#SPECULATE_word::might, may, should, could, 
               
               
                  would 
               
               
                 argument initialization class#TRANSITION_phrase::let us 
               
               
                   
               
             
          
         
       
     
     Appendix B2: Rules Used By e-rater 
     “AFTER” RULE 
     A. Extracts “after”, “after”, and “afterwards” if they occur sentence initially as conjunction. 
     II “ALSO” RULE 
     A. Constrains argument extraction for “also”, classified in the lexicon as arg-init#Parallel, and for additional adverbs classified as arg_dev#Belief such that all are extracted if they appear in sentence initial position or if they modify the main verb of the sentence (defined as the first verb that occurs in the second column of the parse tree). 
     III. LEXICALLY-BASED RULE FOR BEGINNING AN ARGUMENT 
     a. Constrains the extraction of nouns and pronouns clasified as arg-init#CLAIM words in the lexicon to main clause subject NPs and in sentences beginning with “There”, to the position after a form of the verb “to be”. 
     IV. 
     a. Controls the extraction and labeling of Nouns in arg_init position that are modified by “this” or “these” that are labeled arg_dev#SAME_TOPIC when they occur in the second or later sentence of a paragraph. 
     b. If “This”, “These” or “It” occur as a pronoun in the first noun phrase of the parse tree of sentences that are not paragraph-initial, they are output with the label arg_dev#SANE_TOPIC. This label is generated dynamically. “This, “these” and “it” are not stored in the lexicon. 
     V. “BUT” RULE 
     A. Extracts “but” if it is labeled as a conjunction. 
     VI. COMPLEMENT CLAUSE RULE 
     A. Extracts complement clauses introduced by “that” as well as complement clauses that do not begin with “that.” 
     B. Labels complement clause as arg_init#CLAIM_THAT* when it is the first or only sentence of a paragraph, otherwise it is labeled as arg_dev#CLAIM_THAT* 
     C. Extracts the conjunction “that” if it occurs in a complement clause, or a complement clause not introduced by “that” under the following conditions: 
     1. the complement clause is not embedded in another COMPCL or SUBCL 
     2. the complement clause is not further embedded than the third column of the parse tree 
     VII. SUBORDINATE CLAUSE” RULE FOR BEGINNING AN ARGUMENT 
     A. If the very first sentence of a paragraph begins with a subordinate clause, extract the noun or pronoun from the main clause NP and consider it to be the beginning of a new argument. The noun or pronoun extracted is labeled arg_init#D-SPECIFIC if it is not listed in the lexicon. 
     VIII. “FIRST” RULE 
     A. Constains words listed in lexicon that are classified as arg_init#Parallel words. 
     B. All words of this category in sentence initial position are exacted (cf ALSO RULE). 
     C. If the word is not sentence-initial one of the following conditions must be satisfied. 
     1. It must be in the first constituent of the parse tree, provided that the first consituent is not asbordite clause and that it is not further embedded in the parse tree than the third column. 
     2. It must be the first NP following a sentence-initial adverb. 
     3. If the first consistent is the pronoun “I” followed by a verb, then the “FIRST” item must be immediately following the verb. 
     IX. “FURTHER” RULE 
     A. Extracts “further” “overall” or “altogether” if they occur sentence-initially and do not modify another constituent. 
     X. INFINITIVE CLAUSE RULE 
     A. Extracts an infinitival clause that is not further embedded than the third column of the parse tree and either follows or precedes the main verb of the sentence. The clause is not embedded in a subordinate clause or a complement clause. Infintival clauses that are extracted are labeled as arg_init#To-INFL if it is the first or only sentence of a paragraph, otherwise arg_dev#To_INFL. 
     XI. RULE FOR BEGINNING AN ARGUMENT AT A NEW PARAGRAPH 
     A. If a paragraph has no lexical or structural argument initializations then a label arg_init#NEW_PARAGRAPH is applied. 
     XII. “OR” RULE 
     A. Extracts the conjunctions “or” and “either” when they occur in the second column of the parse tree, and the node immediately following the conjunction is a verb phrase. 
     XIII. PARALLEL TERM RULE 
     A. Prevents the extraction of arg_init#Parallel lexical entries terms if they modify a verb or a noun at any level of embedding (cf also FIRST.DOC) 
     XIV. “SHOULD” RULE 
     A. The words, would, should, might, may, and could are be picked up for each essay. They are classified as arg_aux#SPECULATE in the lexicon. 
     B. These words occur in parse trees in the structure 
     C. AUXP VERB “_” 
     XV. “SO” RULE 
     A Extracts the conjunction so if it occurs initially in a subordinate clause or if it is a sentence-initial adverb. 
     XVI. “THEN” RULE 
     A. Extracts “then” if it occurs as an adverb or a conjunction that is not further embedded than the second column of the parse tree. 
     XVII. VERBING RULE 
     A. Extracts sentence-initial nouns and verbs ending in “-ing”, as well as “-ing” verbs that immediately follow a prepositional phrase or an adverb that is in the second column of a parse tree. These extracted “-ing” words are labeled as arg_init#CLAIM_Ving if in the first or only sentence of a paragraph, and arg_dev#CLAIM_Ving otherwise. 
     B. If the base form of the verb is “do”, then the label will be arg_dev#Inference. 
     XVII. “WHEN” RULE 
     A. Extracts all occurrences of “when” in the following structure 
     I. ABBCL* CONJUNCTION PHRASE* CONJUNCTION* “when” if this structure occurs no further embedded than the fourth column of the parse. 
     XIX. “WHILE” RULE 
     A. Extracts “while” under the following conditions. 
     1. It is the first constituent of a sentence 
     2. It is a conjuction in a subordinate clause that is not further embedded than the third column.