=Paper=
{{Paper
|id=None
|storemode=property
|title=Requirements for Developing Strategic Decision Facilitation and Event Prediction Tools
|pdfUrl=https://ceur-ws.org/Vol-818/paper9.pdf
|volume=Vol-818
}}
==Requirements for Developing Strategic Decision Facilitation and Event Prediction Tools==
Requirements for Developing Strategic Decision Facilitation and Event Prediction Tools Oscar Kipersztok Boeing Research & Technology P.O.Box 3707, MC: 7L-44 Seattle, WA 98124 oscar.kipersztok@boeing.com Abstract forecast, will be able to better focus computational resources and minimize (as far as possible) the quantified This paper describes the requirements of a uncertainty over the most relevant aspects of the forecast. strategic decision facilitation tool that relies on The goal of this paper is to clarify the requirements of a forecasting to support critical decisions. A strategic decision facilitation tool that relies on hypothesis-driven (data supported) system rather forecasting to support critical decisions. than a purely data-driven methodology. It further describes the importance of simple and Such system will offer users maximum flexibility and natural human-computer interactions that provide quick turn-around through a decision facilitation simplify the creation of complex domain models process that allows: a) easy capture and organization of in a system that uses probabilistic reasoning knowledge, b) building complex models that can be methods to facilitate high-quality decision readily queried about future events, c) applying advanced making under uncertainty. Such a system helps algorithms, made transparent to users, to forecast users create complex models, query them for predictions, d) searching and piecing together relevant predictions, formulate hypotheses and validate and coherent argumentation in favor (or against) courses their prediction with evidence retrieved from a of action; and e) making actionable recommendations to corpus of text documents. The system must have facilitate significant strategic decisions. a technology to automatically assemble and explain the forecasts so that users--who should 2 KEY COMPONENTS not be required to understand the mathematics There are four key components to a forecasting system behind the forecast--will be able to understand that will be discussed to facilitate high-quality decision- why certain predictions are being made. making: 1. the forecasting algorithms should have access to the context of decisions under consideration, not 1 INTRODUCTION simply the raw data--that is, they should be hypothesis- A principal goal in any forecast of future events is to help driven; 2. the system should enable simple and natural decision-makers deal with uncertainty. Our pictures of human-computer interactions to allow forecasting directly the present and the past are always incomplete and noisy. over concepts of relevance and importance to the decision So uncertainty is ubiquitous. A deeper concern is not just makers; 3. the simplicity of user interaction should not the future, but even our theories and models of how prevent the use of advanced probabilistic reasoning events will unfold that are underdetermined by our data. methods to quantify and minimize uncertainty over Thus, forecasting from data alone is not sufficient and it forecasts; and, lastly, 4. the system should be capable of can be improved by embedding the forecast technology automatically constructing explanations of forecasts within a larger framework for decision support. Such a which can be understood without requiring users to framework can supplement our raw data with information master the details of the forecasting algorithms. Together, about the appropriate context in which to interpret the these components yield a complete decision-support framework that allows for ongoing critical evaluation and validation of high-quality forecasts created. 3 HYPOTHESIS DRIVEN METHODOLOGY 3.1 HYPOTHESIS VERSUS DATA DRIVEN There is a body of evidence in experimental psychology suggesting different modalities in the way people make decisions; some modalities result in more accurate decisions than others (Heuer, 1999). In general, there is the distinction between “data-driven” and “hypothesis- driven” decision making. In the former, the emphasis is on initial search and gathering of as much information as possible before raising a hypothesis leading to an informed decision. In the latter, the emphasis is on a more selective and guided information search driven by a prior hypothesis. An iterative process follows where the search is aimed at specific information enabling validation or rejection of the hypothesis. The hypothesis is either accepted with sufficient evidence or re- formulated based on insufficient evidence. Validated hypotheses with sufficient evidence, in general, lead to more accurate decisions. Our decision support system is architected to direct users to follow a process that in practice has been shown to result in more accurate decisions. Figure 2a: Knowledge capture and representation Figure 1: Sequential steps and feedback in hypothesis- driven decision making 4 SIMPLE AND NATURAL HUMAN COMPUTER INTERACTION This section describes basic human computer interaction principles used to facilitate the creation of complex domain models while making transparent the complexity of analytic methods. Figure 2 shows the three types of analytic methods required by the decision facilitation tool: 2a) knowledge representation and capture, 2b) reasoning inference and 2c) text processing and search methods. Figure 2b: Reasoning methods of concept definitions and causal relations between them. Most concepts affect or are affected by other concepts. In most realistic domains there is feedback where a particular concept starts a causal chain feeding back to itself. Feedback loops can induce complex reinforcing or inhibiting dynamic behavior. The “mental model” is critical because it is used to make predictions and to process and interpret outside information. 4.3 FREE LANGUAGE, ASSOCIATION AND BRAINSTORMING The use of free language in model creation enables more flexibility in building models. Concepts are defined and labeled with short phrases or using a few words. To reduce ambiguity, users further expand concept definition by providing added descriptions for more precise meaning. Concepts are defined based on specific assumptions that also need to be captured. Additional documents and information (e.g. names, locations, specific dates, events, etc.) are also associated with each Figure 2c: NLP & Text Processing concept for further clarification. The use of free language serves a dual purpose. Firstly, the words and phrases used to define the concepts are also used in the creation of a Three corresponding screens have been designed as user rule- based search engine to improve the recall and interfaces to allow users to build models by defining precision of retrieved content needed to substantiate the concepts and their associations, allowing to query the decisions. Secondly, the concept definitions and attached model and make predictions by making assumptions descriptions are also used to create chains of rationale that based on existing facts or beliefs, and searching for will provide explanations to subsequent predictions. information through a corpus of documents in order to validate the assumptions and predictions. 4.4 COMPLEXITY MANAGEMENT AND SCALABILITY These methods are used to provide maximum flexibility and ease of use for rapid model creation, immediate query Automated knowledge capture should be made easy for response and prediction, and fast document retrieval for the user. It should be just as easy to build models of high forecast validation. complexity as it is very simple models. The user should not be concerned with how the knowledge is being 4.1 TRANSPARENCY OF ANALYTIC captured, represented and organized. Users should be able METHODOLOGY AND TERMINOLOGY to add or subtract information to and from the model with ease and at will. Quantity of information should not be of Advanced analytic methods often require familiarity with concern to users. The information should be easily complex methodology. In our approach to modeling accessible at any time during the model building process, complex domains, it is not necessary for users to learn or later during the analysis phase. Providing flexibility to and familiarize with analytic methods. users during model creation in a free-associative, By making the analytic methods transparent, users brainstorming fashion is important since it enables: a) interact with the system by only using the familiar adequate coverage of the domain, leaving no stone language of their domain. Domain concepts are defined unturned; b) seamless scalability to large, complex using free language and users can add to those definitions domains; c) collaborative multiple-user participation with to make their meaning more precise. This eliminates the access to second opinions and feedback; d) ease of model need for knowledge engineers to acquire and convert user refinement and evolution at any future time; and e) speed knowledge and expertise into computational models. - quick addition and deletion of ideas without concern about performance or limits of scalability. Building 4.2 KNOWLEDGE AND RATIONALE models fast, with ease and with transparent complexity CAPTURE management, enables users to build unconstrained models of any size. The knowledge is represented using The model creation process is the most critical step. Users constructs that are readily mapped into graphical create a “mental model” of their domain, which consists 3 probabilistic networks for subsequent forecasting and nodes (Expected time to effect will be discussed in section predictive analysis. 5.2). Alternative methods for building the networks and their 5 PROBABILISTIC REASONING conditional probability tables require obtaining METHODS probability estimates directly from domain experts for each combination of child and parent nodes’ states. This This section describes the creation behind-the-scenes, tedious process can be aided by methods developed for following the construction of the unconstrained mental probability elicitation (Wang, 2004). A major goal of our model, of a Bayesian network for making probabilistic approach, however, is to circumvent this difficulty and forecasts of events and trends. make the process of building models readily accessible to users without need of expertise in graphical probabilistic 5.1 FORECASTING PROBABILITY, IMPACT methods. In either case, once the models are built, their AND TIMING OF EVENTS performance and robustness can be validated using Analysis and prediction methods must be compatible with sensitivity analysis which can help identify the parameters knowledge representation and acquisition constructs used that are most influential for any given query and in the knowledge capture phase. In addition to defining prediction (Kipersztok and Wang, 2003). concepts and relations, analysis methods require Analysts and decision makers require probability additional quantitative input parameters that need to be estimates to guide strategic decisions. In order to maintain obtained from the user during model creation. In the spirit the simple and natural human-computer interface, our of devising easy ways to capture knowledge directly from approach limits the decision space to predictions of event users, the number of requested variables is kept to a occurrences and trends. Decision makers need to know: minimum. Methods were developed to map those a) how probable occurrences of events or emerging trends variables to fit the requirements of the analysis and are; b) the magnitude of their impact; and c) the time inference algorithms. Quantitative inputs should be when such events are expected to occur. Probabilistic acquired from the user in an intuitive manner within the models, in particular graphical models, provide capability context of the familiar user’s domain. to handle problems where data and information may be sparse, noisy or incomplete. In addition to rapid knowledge capture during model building, our methods also provide quick turn-around forecasting during the prediction phase. As part of our on-going effort, we have built prototypes of the system. (Kipersztok, 2007) describes in more detail the implementation of various features of the system. The system has been applied to several specific domain areas. In (Seidler, et. al., 2010), the authors describe the DecAid system which was used to model and predict the readiness of a country to possess nuclear weapons capability. The paper reviews the domain associations used to build an unconstrained model. The model predictions were used to retrieve textual documents with information on Iran’s nuclear program and to compile the risk assessment against the hypothesis that they are building a nuclear Figure 3: Request minimal number of parameters weapon. 5.2 REASONING ABOUT EVENT TIME The qualitative and quantitative inputs variables are New methods are being developed that allow for shown in Figure 3. These are used to populate the probabilistic reasoning over systems evolving in parameters of graphical probabilistic (Bayesian) continuous time (Nodelman, et. al., 2002). These networks. The numbers represent the weight of causal techniques allow direct computation of distributions over belief that the user associates with each relation between when events of interest may occur. Moreover, they allow pairs of concepts in the model. The relations and the for automatic focusing of computational resources on belief numbers are used to build the structure and the those portions of the domain that may undergo rapid conditional probability tables of the Bayesian networks by change. Larger, unified models over domains which combining the weights of causal belief of incoming parent include variables with widely divergent rates of change 4 can thus be made computationally tractable. Machine learning algorithms can be used to help discover underlying structure in context where connections within the data are poorly understood (Nodelman, et. al., 2003). There are already, in the literature, reviews of the advantages of these methods over traditional discrete-time probabilistic models--for instance, showing that the discrete-time models are subject to artifacts from the fixed time granularity and are less efficient to learn than the continuous time models (Nodelman, 2007). Adoption of these methods has been slow due to lack of exposure, limited software support, and ongoing research and development. We define the expected-time-to-effect as one additional quantity to be provided by the user for each concept-pair relation defined in the model (Figure 3). Just as the weight of causal belief is used to create conditional probability tables in Bayesian networks; the addition of expected- time-to-effect is used for the construction of transition matrices in underlying continuous-time Bayesian networks. In this manner the system also can forecast the timing of events. 5.3 IDENTIFICATION OF CONCEPTS RELEVANT TO A QUERY Experimental psychology experiments show that a critical number of variables is needed to make predictions at a fixed level of accuracy. Adding more variables to the Figure 4: Creation of a predictive model (DAG) decision increases the expert’s confidence, without necessarily improving the accuracy of the prediction (Oskamp, 1965)(Shepard , 1964). This emphasizes the importance of being able to determine the critical, relevant concepts associated with a specific query. This 5.4 INDIVIDUALS VS. COLLECTIVE JUDGMENT – CONSENSUS VS. important feature of our decision facilitation system is DISENTING OPINIONS based on research done on relevance and feature selection learning algorithms (Druzdzel and Suermondt., 1994)(Fu A system that offers such model building flexibility and and Desmarais, 2008b). quick turn-around in decision-facilitation and forecasts can be equally effective for use by a single analyst as well Querying the model triggers a prediction. A query is a as by a collective group of decision makers. Difficult and request for predicting the future state of a ‘target’ concept significant decisions are often arrived at by consensus in a given the assumptions about the current state of a set of group setting. Collective consensus is often built around a ‘source’ or ‘trigger’ concepts. The model can contain any particular set of assumptions, a hypothesis, and a number of concepts and associations, but for each query prediction. Once this occurs, it becomes increasingly the ‘source’, the ‘target’ and the set of ‘relevant’ concepts difficult to deviate from the consensus opinion. are the critical set of concepts that matter. Consensus can often be dominated by a vocal minority Once the model is complete the system is ready for within a group at the risk of ignoring dissenting but inference and prediction, based on a specific query. At the equally, or more, valid alternative opinions. time when the query is made, the system identifies the In our system, various parallel hypotheses can be variables and relations relevant to that query and that formulated with ease and subject to different sets of subset of the unconstrained model is converted into a assumptions. With our proposed approach, a single team predictive model (Figure 4). member may be capable of quickly making predictions and forecasting scenarios based on a dissenting hypothesis, while at the same time compiling evidence that can be used to steer the consensus opinion in a 5 different direction that may, convincingly, lead to a because it narrows the search for specific information as different and possibly better decision. evidence for clearly stated assumptions; thus, lending credibility and validity to the predictions. Precise concept 6 FORECAST VALIDATION AND definitions and rationale that explain concept relations EXPLANATION together with gathered evidence from search make it possible to support a hypothesis-driven prediction. In In (Lacave and Díez, 2002), the authors review various arriving at critical decision, the facilitation methods explanation methods for Bayesian networks and argue, on discussed can help users step through a process that helps the one hand, that the normative approach for building capture knowledge and data, organize them, invoke expert systems, based on probabilistic reasoning, leads to analysis methods to forecast predictions, piece together more robust and accurate results. On the other hand, they evidence, and rationale for or against courses of action, also require more explanation capability because the and make actionable recommendations. The final choice methods are more foreign to human beings than in the of action must be ultimately made by humans. The system heuristic approach. will compute and present the necessary trade-offs between risk and cost for each recommended course of Here, we are suggesting that much of the information to action. be presented as explanation during inference and prediction can be captured upfront, during the model Retroactive historical analysis constitutes another building phase. It is part of the contextual knowledge validation approach. It entails making predictions of past imparted by the user as concepts and relations are defined. events and comparing the model forecast to actual A very specific context and specific assumptions are outcomes. Predictions can also be compared among made for every concept and causal relation defined in the different methods. unconstrained model. The weight-of-causal- belief and the expected-time-to-effect are quantities also defined subject 6.3 RAPID PROTOTYPING - ‘WHAT IF” to very specific assumptions. The system allows for user SCENARIOS to systematically add such context during the model creation phase. The information is organized so that it is Being able to quickly build complex mental models, and readily available for retrieval at the time that the having the underlying machinery to automatically convert explanation is needed. the created entities and relations into analytic models to make immediate predictions, provide single or multiple users with great flexibility. A single user can in one 6.1 EXPLANATION AND CHAIN OF sitting use their knowledge to build a complex model, REASONING define concepts and relations, document their rationale, Predictions of highly probable events, of high impact and query the model to make predictions, and search for possibly occurring in the near future will be of most evidence to validate a new hypothesis. A quick turn- interest to users. Before courses of action are decided, around decision facilitation method like ours enables decision makers require explanations that support a users to postulate various ‘what-if’ scenarios and test particular prediction and its assumptions. In addition, they parallel hypotheses side by side. also require convincing evidence that can back the predictions with plausible and believable facts. 6.4 AUTOMATED DOCUMENTATION AND Qualitative explanations are provided by showing the SUMMARIZATION causal chains of reasoning from trigger assumptions to predicted target outcomes where the entire relevant Our system automatically compiles and packages all the context that was captured during model building is information needed for a strategic decision by organized and presented in every step along various paths summarizing the hypothesis and its assumptions, together of reasoning. Rationale captured and documented by the with the associated evidence, the forecasts and the chain users, together with evidence retrieved from document of reasoning explaining the prediction in the context of search, constitute the basis for the explanation given to the specific concept definitions and the assumptions made decision makers associated with forecasts and predictions when causal relations were defined. This capability to by the system. provide a summary documentation of the prediction, the assumptions and its explanation can be made available to second parties for critique and revision before actions of 6.2 INFORMATION RETRIEVAL- significant consequence are taken. VALIDATION THROUGH SEARCH In political, cultural and socio- economic domains, validation often comes from validated evidential facts. Having a hypothesis makes the search more efficient 6 7 SUMMARY Lacave, C. and Díez, F. J. (2002). "A review of Requirements for a decision facilitation system are explanation methods for Bayesian networks", Knowl. presented that describe human- machine interface Eng. Rev., vol. 17, p.107 , 2002. concepts that simplify for users the creation of complex domain models, while making transparent the analytic Nodelman, U., Shelton, C. R., and Koller, D. (2002). methodology that requires additional, specialized Continuous Time Bayesian Networks. Proceedings of the expertise. Those simplifying features are built into the Eighteenth Conference on Uncertainty in Artificial user-interface to help users step through the creation of a Intelligence, pp. 378-387, 2002. model, query the model to make predictions, formulate hypotheses and validate the prediction from searched Nodelman, U., Shelton, C.R., and Koller, D. (2003). evidence (for or against) retrieved from a large corpus of Learning Continuous Time Bayesian documents. Explanation to predictions combines the Networks. Proceedings of the Nineteenth Conference on rationale captured from the user during model Uncertainty in Artificial Intelligence, pp. 451-458, 2003. development and the evidence gathered in support of a hypothesis; and it is presented to decision makers in Nodelman, U. (2007). Continuous Time Bayesian context along the various paths of causal inference. Networks. Ph.D. Dissertation, Stanford University. 2007. Acknowledgments Oskamp, S., (1965). Overconfidence in Case-Study Judgments, Journal of Consulting Psychology, 29, 1965, Very special thanks to Uri Nodelman for his insightful pp. 261-265, 1965. comments and feedback; and for his valuable contribution in the area of temporal reasoning. Shepard, R. N. (1964). On Subjectively Optimum Selection Among Multi-attribute Alternatives, in M. W. References Shelly, II and G. L. Bryan, eds., Human Judgments and Optimality, New York: Wiley, 1964, p. 166, 1964. Druzdzel, M., Suermondt, H. (1994). 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