Showing papers on "Representation (systemics) published in 1977"

Schemata as Scaffolding for the Representation of Information in Connected Discourse. Technical Report No. 24.

Abstract: Information that is significant in the light of die conceptual framework, or “schema,” within which a text is interpreted ought to be better learned and recalled than less significant information. This hypothesis was evaluated in an experiment in which college students read narratives about a meal at a fine restaurant or a trip to a supermarket. The same 18 items of food, attributed to the same characters, were mentioned in the same order in the two stories. As predicted, foods from categories determined to be part of most people’s restaurant schemata were better recalled by students who read the restaurant narrative. Also as predicted, students who received the restaurant narrative were more likely to recall the character to whom a food had been attributed. However, contrary to expectation, participants were equally likely to reproduce food-order information whichever passage they had read. Information of the same significance in the context of either the restaurant or supermarket story was equally well recalled by the two groups.

The representation and use of focus in dialogue understanding.

Abstract: : This report develops a representation of focus of attention thatcircumscribes discourse contexts within a general representation ofknowledge. Focus of attention is essential to any comprehension processbecause what and how a person understands is strongly influenced bywhere his attention is directed at a given moment. To formalize thenotion of focus, the need for and the use of focus mechanisms areconsidered from the standpoint of building a computer system that canparticipate in a natural language dialogue with a ser, Two ranges offocus, global and immediate, are investigated, and representations forincorporating them in a computer system are developed.The global focus in which an utterance is interpreted is determinedby the total discourse and situational setting of the utterance. Itinfluences what is talked about, how different concepts are introduced,and how concepts are referenced. To encode global focuscomputationally, a representation is developed that highlights thoseitems that are relevant at a given place in a dialogue. The underlyingknowledge representation is segmented into subunits, called focusspaces, that contain those items that are in the focus of attention of adialogue participant during a particular part of the dialogue.Mechanisms are required for updating the focus representation,because, as a dialogue progresses, the objects and actions that arerelevant to the conversation, and therefore in the participants' focusof attention, change. Procedures are described for deciding when andhow to shift focus in task-oriented dialogues, i.e., in dialogues inwhich the participants are cooperating in a shared task. Theseprocedures are guided by a representation of the task being performed.The ability to represent focus of attention in a languageunderstanding system results in a new approach to an important problemin discourse comprehension -- the identification of the referents ofdefinite noun phrases.

Measuring Representation: Perils of the Correlation Coefficient

Abstract: Most empirical research on representation has used correlational measures. The larger the correlation between representatives' and constituents' views, the stronger the bonds between them are thought to be. Unfortunately, correlations incorporate not only the strength of a relationship, but also the diversity of the sampled constituencies. When constituencies are very different from each other on an issue dimension, large correlations will result even when voters are not particularly sensitive to that dimension. Large correlations can occur when representatives are distant from their constituents; small correlations can happen when they are near. Correlations should be abandoned in the study of representation.

The representation and use of focus in a system for understanding dialogs

Abstract: As a dialog progresses the objects and actions that are most relevant to the conversation, and hence in the focus of attention of the dialog participants, change This paper describes a representation of focus for language understanding systems, emphasizing its use in understanding task-oriented dialogs The representation highlights that part of the knowledge base relevant at a given point in a dialog A model of the task is used both to structure the focus representation and to provide an index into potentially relevant concepts in the knowledge base The use of the focus representation to make retrieval of items from the knowledge base more efficient is described

Children's Judgments of Numerical Inequality.

Abstract: SEKULER, ROBERT, and MIERKIEWICZ, DIANE. Children's Judgments of Numerical Inequality. CHILD DEVELOPMENT, 1977, 48, 630-633. When adults judge which of 2 digits is numerically larger, their response times decrease linearly with the numerical difference. For children in fourth and seventh grades, the function relating judgment time to numerical difference has the same slope as that of adults. For children in kindergarten and first grade the function is considerably steeper. This may reflect a developmental change in the internal representation of the number series.

Representing Visual Information

Abstract: : Vision is the construction of efficient symbolic descriptions from images of the world An important aspect of vision is the choice of representations for the different kinds of information in a visual scene In the early stages of the analysis of an image, the representations used depend more on what it is possible to compute from an image than on what is ultimately desirable, but later representations can be more sensitive to the specific needs of recognition This essay surveys recent work in vision at MIT from a perspective in which the representational problems assume a primary importance An overall framework is suggested for visual information processing, in which the analysis proceeds through three representations; (1) the primal sketch, which makes explicit the intensity changes and local two-dimensional geometry of an image, (2) the 2 1/2-D sketch, which is a viewer-centered representation of the depth, orientation and discontinuities of the visible surfaces, and (3) the 3-D model representation, which allows an object-centered description of the three-dimensional structure and organization of a viewed shape Recent results concerning processes for constructing and maintaining these representations are summarized and discussed (Author)

The Volterra Representation and the Wiener Expansion: Validity and Pitfalls

Abstract: Volterra and Wiener series provide a general representation for a wide class of nonlinear systems. In this paper we derive rigorous results concerning (a) the conditions under which a nonlinear functional admits a Volterra-like integral representation, (b) the class of systems that admit a Wiener representation and the meaning of such a representation, (c) some sufficient conditions providing a connection between the Volterra-like and the Wiener representations, (d) the mathematical validity of the method of Lee and Schetzen for identifying a nonlinear system.

Anaphora and logical form: on formal meaning representations for natural language

Abstract: We argue, on general grounds, in favor of formal meaning representations for natural language. We then adopt, as a "Forcing function" for the adequacy of such as representation the problem of identifying the possible antecedents of anachoric expressions. This suggests certain structural properties of a representation which facilitate the identification of a possible antecedents. Given an appropriate representation. language with such properties, it is then possible to deal with a surprisingly rich class of anachora.

Knowledge acquisition from structural descriptions

Abstract: : The representation of concepts and antecedent-consequent productions is discussed and a method for inducing knowledge by abstracting such representations from a sequence of training examples is described. The proposed learning method, interference matching, induces abstractions by finding relational properties common to two or more exemplars. Three tasks solved by a program which performs an interference matching algorithm are presented. Several problems concerning the relational representation of examples and the induction of knowledge by interference matching are also discussed.

Target with removable score sheet

Abstract: A target is shaped in the form of an animate object, preferably, simulating an animal. The target is formed from any suitable material which can receive a projectile impacting thereagainst. The target is provided with a torso opening in which is emplaced a graphic representation of the internal organs of the animal so simulated. The present target is particularly adapted for use in archery.

The Influence of Representation on Public Policy

Abstract: IN a recent paper' Stigler formulated and tested a simple model of the relative influence of United States Senators versus members of the House of Representatives. He sought to explain the distribution of federal grants and non-defense employment across states by regressing the number of house members against these two measures of political influence, with the relative influence of a senator versus a representative being implicit in his estimation procedure. Though not robust, his results show a relatively large impact of two senators versus the entire house delegation (that is, relative weights of 1.02 in the case of grants and 2.42 in the case of employment). Although he did not advertise his approach to this question as an elaborate one, Stigler made an implicit assumption that can be improved upon. He assumed a one man-one vote correspondence, since all representatives in a legislative body are treated as equals in his model. Yet representatives and senators are not homogeneous in their ability to influence expenditure or employment decisions if institutional variables such as seniority influence their productivity. In this paper we develop an empirical inquiry in the spirit of Stigler that controls for the non-homogeneity of a state's House and Senate delegations and tries to account for the pattern of federal expenditures across states. Our model is not a one man-one vote model, but a weighted voting analogue based on seniority institutions. In Section I we review Stigler's approach and offer an initial extension which accounts for seniority differences across state House and Senate delegations. This extension is tested empirically and the results are contrasted to those of Stigler. While the findings for House delegations are essentially consistent with those of Stigler, those for Senate delegations show, surprisingly, no influence of the seniority of senators on an expenditure measure of public policy outcomes. We offer an explanation of these results stressing the constitutional primacy of the House in the budgetary process. We also dis-

The sphere of influence

Abstract: This is a study of network representation: The data represent a set of interlocked directorates—specifically, the network in which the boards of major banks are interlocked with the boards of major industrials. The problem is to represent this network so as to organize it and describe its major outlines. Using an unfolding variant of smallest space analysis, the problem is solved by a spherical map: the “Sphere of Influence.” The sectors of the sphere represent similarly-linked corporations, and the relations among the sectors represent the relations among bank-industrial communities.