Goal-based Decision Making

An Interpersonal Model

Stephen Slade

• Publisher: Psychology Press
• Year: 2013
• ISBN:
  9781134779178
• Edition: 1
• Topic: Psychology
• Subtopic: History & Theory in Psychology
• Index: Psychology

This work presents a goal-based model of decision making in which the relative priorities of goals drive the decision process -- a psychological alternative to traditional decision analysis. Building on the work of Schank and Abelson, the author uses goals as the basis for a model of interpersonal relations which permits decisions to incorporate personal and adopted goals in a uniform manner. The theory is modelled on the VOTE computer program which simulates Congressional roll-call voting decisions. The VOTE program expands traditional decision making and simulation models by providing not only a choice, but also a natural language explanation, in either English or French. It simulates real members of Congress voting on real bills, and producing reasonable explanations. The program is consistent with much of the descriptive political science literature on Congressional decision making and provides an explicit model of political issues, relationships, and strategies that converge in voting behavior. In developing the VOTE program, the author draws on his own practical experience in politics from four presidential campaigns and the White House. Given the underlying psychological basis of the program, VOTE can be extended to other decision making domains different from politics. Another use for the program is to simulate business decisions such as securities analysis, as well as mundane decision making such as choosing a college or deciding whether to get a Mohawk haircut.

Chapter 1

Goals and Decisions

Chapter Summary

This chapter introduces the main topics of discussion. First, we describe our focus on goals and intentions for decision making. Second, we discuss the dimension of importance in goal-based reasoning. Third, we present a process model for the task of decision making. Fourth, we provide a brief example of the VOTE program, which simulates Congressional roll call voting decisions. We conclude this chapter with an overview of the remaining chapters.

1.1 Introduction

A realistic model of decision making must account for a multitude of goals and limited resources. Many problems will not admit perfect solutions. Practical decisions often involve trade-offs. Examples of such choices include buying a car or a house, prescribing a medical treatment, purchasing computer hardware and software, or getting married.

Standard prescriptive models of decision analysis [Raiffa, 1968] maximize an expected value based on the probabilities and payoffs of different possible outcomes. We propose an alternative descriptive model of decision making based on an analysis of an agent’s goals, past behavior, and relationships with other agents. Our model suggests that a decision maker has a multitude of goals beyond simply maximizing payoffs and minimizing risks. The agent’s goals include both personal goals and adopted goals derived from interpersonal relationships. The agent must resolve goal conflicts by making trade-offs.

In this goal-based model of decision making, the relative priorities of goals drive the decision process. This model serves as the basis for the VOTE program which simulates Congressional roll call voting decisions, based on the relative priorities of goals and constituent relationships, as well as the need to provide an explanation for the decision.

In developing the role of goals and priorities in decision making, we view goals not as atomic entities, but as composite objects with a defined structure. Goals are complex. We explore a number of significant dimensions of goals, and develop a broad range of types of goals that share basic properties relevant for decision making.

1.2 Ubiquitous Goals

Goals are a pervasive element of our language and thought. Consider the following excerpts from articles in the New York Times of September 21, 1990.

MOSCOW.… “I am from a peasant’s family and I want my people to live better,” said [Stanislav Shatalin] this avid free-enterprise economist, whose grand scheme for national renewal may finally reach the initial voting stage in Parliament on Friday amid a welter of confusion and anxiety about the moribund economy. [page A1]

BONN. Chancellor Helmut Kohl of West Germany pledged today that a united Germany would remember its responsibility for the genocide of European Jews and fight anti-semitism. “Germany will stand firm in recognizing this historical responsibility in the future,” he said in a special message marking Rosh ha-Shanah, the Jewish New Year. [page A2]

MANILA. The Government wants the United States military to hand over control of Clark Air Base when the security treaty between the two countries expires in September 1991, a spokesman for the Philippine negotiators said today. [page A4]

WASHINGTON. The United States opposed the latest attempt at Persian Gulf peacemaking by King Hussein of Jordan and has been lobbying among the Arab nations against proposals that would offer any advance concessions to gain Iraqi withdrawal from Kuwait, a senior Administration official said today. [page A9]

NEW YORK. What many prospective home buyers in Queens seem to share is the desire for a place to live that has its own entrance, an attached garage and a backyard they can call their own. [page A20]

BOGOTA. The kidnappings of a prominent journalist and a relative of a former top Government official may be part of a plan by the country’s cocaine cartels to put pressure on the Government to enter into negotiations, the police said today. [page A11]

The above quotations provide explicit and implicit statements of goals. The following stories involve other aspects of goal pursuit, such as projections of the likelihood of achieving a goal, or the need to modify a goal or a plan.

ABIDJAN, Ivory Coast. After visiting Liberia to assess the civil war there, a senior American official has said prospects for a negotiated settlement of the conflict appear to be diminishing. [page A7]

WASHINGTON. In an effort to head off a battle with critics in Congress, the Bush Administration is considering modifying a plan to sell $21 billion in arms to Saudi Arabia. [page A9]

WASHINGTON. Legislation permitting a vote by Puerto Ricans on the United States commonwealth’s political future could come to the floors of the House and Senate this year, but its supporters said today that time was running out for the bill’s final passage. [page A13]

The following three stories illustrate the way in which a decision may require justification to the degree that its consequences violate goals.

MADRID. The dispatch of three Spanish warships may have done little to tip the strategic balance in the Persian Gulf, but it has stirred a stormy debate in Spain over whether this long-isolated country should become more involved in world affairs. [page A10]

BUENOS AIRES. President Carlos Saúl Menem said today that a growing storm of protest at home would not stop him from sending Argentine warships and officers to join the Persian Gulf blockage of Iraq. [page A10]

TOKYO. Olympic leaders defended their choice of Atlanta as host for the 1996 Games against charges today that they sold out to commercial interests. [page A24]

As these examples suggest, through both explicit and implicit reference, we commonly speak of goals, plans, motives, responsibilities, desires, intentions, wants, needs, and many other goal-related concepts. The pursuit of goals, and the concomitant communication, discussion, and evaluation of goals, are prominent parts of human behavior.

Goals may be a ubiquitous phenomenon, yet goals remain abstract. We cannot see a goal. Goals are intangible.

Artificial intelligence (AI) has long recognized the utility of goals in the simulation of human planning and problem solving. Traditional AI models have generally treated goals as uniform, homogeneous constructs. Such goals may be achieved through the execution of plans which are themselves composed of sub-goals. GPS [Newell and Simon, 1963] and the blocks world programs [Winograd, 1972, Sussman, 1975] implicitly accepted the view that a goal was equivalent to a specific desired state of the world. A goal was something to be achieved through some set of actions.

Doyle (1990) recently challenged this view of homogeneous goals. Doyle cites Newell’s Principle of Rationality:

If an agent has knowledge that one of its actions will lead to one of its goals, then the agent will select that action. [Newell, 1982]

Doyle stated that “this principle ignores comparisons among goals and among the different methods for [achieving] goals,” and goes on to endorse an economic theory of choice.

Another perspective on goals was offered by Schank and Abelson (1977). For story understanding tasks, they proposed a broader view of goals which distinguished among a variety of goal types including goals of satisfaction, enjoyment, achievement, preservation, crisis, and instrument. The Schank and Abelson taxonomy was suggestive of the underlying properties of goals.

We propose an extension of the Schank and Abelson view of goals, embracing the following general points.

• Goals are abstract.

• There are many types of goals.

• Goals may combine and interact with other goals.

• Goals may be decomposed into underlying properties.

Our task is to begin to characterize and analyze goals. We shall try to ascertain or propose an underlying structure for goals. We shall use this structure to develop a notation for goals, and to provide an explicit representation for goals. This representation may then serve as the basis for a computational model of intentional behavior, specifically, decision making.

We should also mention that we do not intend to produce a formal semantics for goals. Some AI researchers believe that the way to make a program smart is to provide it with a formal semantics for its knowledge. This notion seems analogous to a belief that the way to become rich is to open a checking account. Being able to write checks and get monthly statements may provide convenient transactions and bookkeeping, but a checking account is neither a necessary nor sufficient condition for wealth. In fact, there are many types of wealth that would not be reflected directly in a checking account, such as real estate, jewelry, or a stock portfolio.

Similarly, we believe that formalizing knowledge representations is neither a necessary nor sufficient condition for endowing computer programs with intelligence. Defining wealth in terms of the balance in a checking account may well ignore many less liquid assets. Formalizing knowledge representations may well ignore less formal types of knowledge.

The time to get a checking account is after you have earned some money. The time to formalize knowledge is after you have acquired some knowledge.

1.3 Chemistry, Music, and Goals

A goal is an abstraction. You cannot see or touch a goal, just as you cannot see or touch gravity. Physicists have postulated forces like gravity to explain the physical world. Gravity is not directly observable, but its effects are. Gravity is a useful theoretical construct for explaining physical phenomena. Goals can play an analogous role in the explanation of human behavior. Gravity is useful in predicting the fall of a leaf from a tree or the motion of planets through space. We suggest that a theory of goals is useful in modeling and explaining individual and interpersonal behavior.

In outlining a theory of goals and decision making, we shall engage in observation and analysis. Across a wide range of disciplines, we note the process of observation, categorization, reduction, and notation. In suggesting that we focus on goals as a topic for classification and analysis, we first offer analogies to other well-established reductive enterprises, namely, the chemical theory of elements, and the development of musical notation.

The kinetic theory of atoms can be traced back to Demokritos (c. 460–370 B.C.) who proposed four basic elements: earth, air, water, and fire. Earlier philosophers, such as Heraklitos, had proposed related theories focusing on but a single “first source” of matter, such as fire.

Over the centuries, the classification of elements expanded and became more refined. Chemists observed standard ways in which elements would combine to form more complex substances. They discovered that the same basic substance, such as water, could occur as a gas, liquid, or solid. Chemists noted standard properties exhibited by the elements themselves, such as atomic weight, valence, specific gravity, boiling point, and density. They developed a systematic notation for chemical elements and compounds.

In 1869, the Russian chemist Dimitri Mendeléev proposed a classification system for the elements that emphasized the cyclical reoccurence of the elements’ chemical properties with increasing atomic weight. Under Mendeléev’s system, elements fell naturally into eight distinct groups. Elements in each group exhibited similar chemical properties. Mendeléev was able accurately to predict the properties of three elements that had not yet been discovered, but which would naturally occur at gaps in his table.

Chemists and physicists were later to discover explanations for the periodic properties in the electron shells of the elements. Mendeléev’s periodic table of elements reflected the fundamental physical atomic structure of matter.

The periodic table and the related chemical notation are abstract concepts that describe and depict natural physical phenomena. Over the centuries, the scientific enterprise of chemistry has refined and expanded our understanding of the underlying properties and physical structure of matter. By analogy, we suggest that a study of intentionality may follow a similar path. We first observe the role of goals in human behavior, and develop taxonomies for classifying different types of goals. We try to discern properties of goals that may lead us to discover an underlying regular structure.

The field of music provides another domain in which observations of a physical phenomenon led to a system of classification and notation. As with chemistry, the Greeks appear to have started the investigation. Early mathematicians, such as Pythagoras, observed the regular relationships between the length of a vibrating string and its pitch.

As western music developed, so did the notation for expressing the underlying atomic unit of music: the note. Just as a chemical element is defined by specific structural properties, a note di...

Table of contents

• Cover
• Title
• Copyright
• Contents
• List of Tables
• List of Figures
• Preface
• Acknowledgments
• 1 Goals and Decisions
• 2 Overview of the VOTE Program
• 3 Goals
• 4 Resources
• 5 Interpersonal Relations
• 6 The VOTE Program
• 7 Decision Strategies
• 8 Related Work
• 9 Future Work
• Bibliography
• Appendix A: Natural Language Generation
• Appendix B: Inside VOTE
• Appendix C: ISSUES
• Appendix D: BILLS
• Appendix E: GROUPS
• Appendix F: MEMBERS
• Index