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  • 301.
    Boman, Magnus
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Holm, Einar
    Multi-agent systems, time geography, and microsimulations2004In: Systems Approaches and their Application / [ed] Olsson, M-O. and Sjöstedt, G., Boston: Kluwer Academic , 2004Chapter in book (Other academic)
  • 302.
    Boman, Magnus
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Johansson, Stefan
    Modeling Epidemic Spread in Synthetic Populations - Virtual Plagues in Massively Multiplayer Online Games2007In: Proceedings of Digital Games Research Association (DiGRA) 2007, 2007, p. 357-361Conference paper (Refereed)
    Abstract [en]

    A virtual plague is a process in which a behavior-affecting property spreads among characters in a Massively Multiplayer Online Game (MMOG). The MMOG individuals constitute a synthetic population, and the game can be seen as a form of interactive executable model for studying disease spread, albeit of a very special kind. To a game developer maintaining an MMOG, recognizing, monitoring, and ultimately controlling a virtual plague is important, regardless of how it was initiated. The prospect of using tools, methods and theory from the field of epidemiology to do this seems natural and appealing. We will address the feasibility of such a prospect, first by considering some basic measures used in epidemiology, then by pointing out the differences between real world epidemics and virtual plagues. We also suggest directions for MMOG developer control through epidemiological modeling. Our aim is understanding the properties of virtual plagues, rather than trying to eliminate them or mitigate their effects, as would be in the case of real infectious disease.

  • 303.
    Boman, Magnus
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Sandin, Anna
    Implementing an agent trade server2006In: Decision Support Systems, ISSN 0167-9236, E-ISSN 1873-5797, Vol. 42, no 1, p. 318-327Article in journal (Refereed)
    Abstract [en]

    An experimental server for stock trading autonomous agents is presented and made available, together with an agent shell for swift development. The server, written in Java, was implemented as proof-of-concept for an agent trade server for a real financial exchange.

  • 304. Boonman, Hettie J.
    et al.
    Siddiqui, Afzal S.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences. University College London, UK; HEC Montréal, Canada.
    Capacity optimization under uncertainty: The impact of operational time lags2017In: European Journal of Operational Research, ISSN 0377-2217, E-ISSN 1872-6860, Vol. 262, no 2, p. 660-672Article in journal (Refereed)
    Abstract [en]

    Time lags in switching operational modes are typical in the manufacturing and power sectors but are not treated in most real options models. In this paper, we consider a firm that has the opportunity to suspend and to resume production infinitely many times subject to a time lag after each startup decision. We contribute to the literature by allowing the firm to determine its level of installed capacity in conjunction with its optimal investment timing. We find that an increase in the length of the time lag results in an increase in the optimal capacity level. Capacity optimization also interacts with the length of the time lag to affect investment timing and the triggers to suspend and resume production, thereby weakening the result about hysteresis from a standard real options model. Under the assumption of a fixed level of capacity, a longer lag speeds up the decision to resume operations due to a positive upside to the revenue but delays the suspension of operations. By contrast, with capacity optimization, a longer time lag results in a larger capacity choice, which can indirectly delay the investment decision and the timing to resume operations. This indirect effect dominates when the level of market uncertainty is low and the time lag is initially small.

  • 305.
    Borg Gyllenbäck, Katarina
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Boman, Magnus
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Narrative Bridging2011In: Design Computing and Cognition ’10 / [ed] John S. Gero, Berlin: Springer Verlag , 2011, p. 525-544Conference paper (Refereed)
    Abstract [en]

    In the design of interactive media, various forms of intuitive practice come into play. It might prove tempting to use templates and strong narrative structures instead of developing the narrative directly for interactive media. This leads towards computer implementation too swiftly. The narrative bridging method focuses on the initial design phase, in which the conceptual modeling takes place. The purpose is to provide designers with a non-intrusive method that supports the design process without interfering with its creative elements. The method supports the sentient construction of digital games with a narrative, with the ultimate goal of enhancing the player’s experience. A prototype test served as a first evaluation, and two games from that test are showcased here for the purpose of illustrating the hands-on use of narrative bridging. The test demonstrated that the method could aid time-constrained design, and in the process detect inconsistencies that could prevent the design team from making improvements. The method also provided teams with a shared vocabulary and outlook.

  • 306. Borking, Kjell
    et al.
    Danielson, Mats
    Davies, Guy
    Ekenberg, Love
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Idefeldt, Jim
    Larsson, Aron
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Transcending Business Intelligence2011Book (Other academic)
  • 307. Borking, Kjell
    et al.
    Danielson, Mats
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Ekenberg, Love
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Idefeldt, Jim
    Larsson, Aron
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Bortom Business Intelligence2009 (ed. 1)Book (Other academic)
  • 308. Bornemann, Leon
    et al.
    Lecerf, Jason
    Papapetrou, Panagiotis
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    STIFE: A Framework for Feature-based Classification of Sequences of Temporal Intervals2016In: Discovery Science: 19th International Conference, DS 2016, Bari, Italy, October 19–21, 2016, Proceedings / [ed] Toon Calders, Michelangelo Ceci, Donato Malerba, Springer, 2016, p. 85-100Conference paper (Refereed)
    Abstract [en]

    In this paper, we study the problem of classification of sequences of temporal intervals. Our main contribution is the STIFE framework for extracting relevant features from interval sequences to build feature-based classifiers. STIFE uses a combination of basic static metrics, shapelet discovery and selection, as well as distance-based approaches. Additionally, we propose an improved way of computing the state of the art IBSM distance measure between two interval sequences, that reduces both runtime and memory needs from pseudo-polynomial to fully polynomial, which greatly reduces the runtime of distance based classification approaches. Our empirical evaluation not only shows that STIFE provides a very fast classification time in all evaluated scenarios but also reveals that a random forests using STIFE achieves similar or better accuracy than the state of the art k-NN classifier.

  • 309. Bornoe, Nis
    et al.
    Barkhuus, Louise
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    TagPad: Supporting Field Interviews and Analysis2013In: iConference 2013 Proceedings / [ed] Linda Schamber, iShools , 2013, p. 316-325Conference paper (Refereed)
    Abstract [en]

    The area of cyberinfrastructures has looked extensively at research within the natural sciences, however, the social sciences have been largely overlooked in terms of novel data collection and analysis systems. We developed a probe tool, TagPad, to look at the process for social science data collection through interviews and surveys. Our research participants found that TagPad facilitated structuring of interviews but we also found that the setting in which the interview takes place is essential to the success of using this particular tool. We conclude suggesting future designs of social science research tools.

  • 310. Boström, Gustav
    et al.
    Henkel, Martin
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Nyfjord, Jaana
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Aspects in the Agile Toolbox2005Conference paper (Other academic)
    Abstract [en]
    The introduction of agile methodologies promises faster time to market and a flexible, customer-driven software development process. The flexibility with regards to requirements can however also be a risk if new non-functional requirements need to be implemented late in a software development project. In this article we argue that aspect-oriented programming is a technique that can mitigate this risk by providing the means to deal with non-functional, crosscutting requirements. The suggested solution is illustrated by an example where new requirements in the form of quality of service demands on an existing service are implemented by using aspect orientated programming.
  • 311. Boström, Gustav
    et al.
    Nyfjord, Jaana
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Bodén, Marine
    Beznosov, Konstantin
    Kruchten, Philippe
    Extending XP Practices to Support Security Requirements Engineering2006In: Proceedings of Workshop on Software Engineering for Secure Systems (SESS’06), 28th International Conference of Software Engineering (ICSE’06), Shanghai, China, 2006Conference paper (Other academic)
  • 312.
    Boström, Henrik
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Calibrating Random Forests2008In: Proceedings of the Seventh International Conference on Machine Learning and Applications, 2008Conference paper (Refereed)
  • 313.
    Boström, Henrik
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Concurrent Learning of Large-Scale Random Forests2011In: Scandinavian Conference on Artificial Intelligence, IOS Press , 2011Conference paper (Refereed)
  • 314.
    Boström, Henrik
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Estimating Class Probabilities in Random Forests2007In: Proceedings of the Sixth International Conference on Machine Learning and Applications, IEEE , 2007, p. 211-216Conference paper (Refereed)
    Abstract [en]

    For both single probability estimation trees (PETs) and ensembles of such trees, commonly employed class probability estimates correct the observed relative class frequencies in each leaf to avoid anomalies caused by small sample sizes. The effect of such corrections in random forests of PETs is investigated, and the use of the relative class frequency is compared to using two corrected estimates, the Laplace estimate and the m-estimate. An experiment with 34 datasets from the UCI repository shows that estimating class probabilities using relative class frequency clearly outperforms both using the Laplace estimate and the m-estimate with respect to accuracy, area under the ROC curve (AUC) and Brier score. Hence, in contrast to what is commonly employed for PETs and ensembles of PETs, these results strongly suggest that a non-corrected probability estimate should be used in random forests of PETs. The experiment further shows that learning random forests of PETs using relative class frequency significantly outperforms learning random forests of classification trees (i.e., trees for which only an unweighted vote on the most probable class is counted) with respect to both accuracy and AUC, but that the latter is clearly ahead of the former with respect to Brier score.

  • 315.
    Boström, Henrik
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Feature vs. Classifier Fusion for Predictive Data - a Case Study in Pesticide Classification2007In: Proceedings of the 10th International Conference on Information Fusion, IEEE , 2007, p. 1-7Conference paper (Refereed)
    Abstract [en]

    Two strategies for fusing information from multiple sources when generating predictive models in the domain of pesticide classification are investigated: i) fusing different sets of features (molecular descriptors) before building a model and ii) fusing the classifiers built from the individual descriptor sets. An empirical investigation demonstrates that the choice of strategy can have a significant impact on the predictive performance. Furthermore, the experiment shows that the best strategy is dependent on the type of predictive model considered. When generating a decision tree for pesticide classification, a statistically significant difference in accuracy is observed in favor of combining predictions from the individual models compared to generating a single model from the fused set of molecular descriptors. On the other hand, when the model consists of an ensemble of decision trees, a statistically significant difference in accuracy is observed in favor of building the model from the fused set of descriptors compared to fusing ensemble models built from the individual sources.

  • 316.
    Boström, Henrik
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Forests of probability estimation trees2012In: International journal of pattern recognition and artificial intelligence, ISSN 0218-0014, Vol. 26, no 2, p. 1251001-Article in journal (Refereed)
    Abstract [en]

    Probability estimation trees (PETs) generalize classification trees in that they assign class probability distributions instead of class labels to examples that are to be classified. This property has been demonstrated to allow PETs to outperform classification trees with respect to ranking performance, as measured by the area under the ROC curve (AUC). It has further been shown that the use of probability correction improves the performance of PETs. This has lead to the use of probability correction also in forests of PETs. However, it was recently observed that probability correction may in fact deteriorate performance of forests of PETs. A more detailed study of the phenomenon is presented and the reasons behind this observation are analyzed. An empirical investigation is presented, comparing forests of classification trees to forests of both corrected and uncorrected PETS on 34 data sets from the UCI repository. The experiment shows that a small forest (10 trees) of probability corrected PETs gives a higher AUC than a similar-sized forest of classification trees, hence providing evidence in favor of using forests of probability corrected PETs. However, the picture changes when increasing the forest size, as the AUC is no longer improved by probability correction. For accuracy and squared error of predicted class probabilities (Brier score), probability correction even leads to a negative effect. An analysis of the mean squared error of the trees in the forests and their variance, shows that although probability correction results in trees that are more correct on average, the variance is reduced at the same time, leading to an overall loss of performance for larger forests. The main conclusions are that probability correction should only be employed in small forests of PETs, and that for larger forests, classification trees and PETs are equally good alternatives.

  • 317.
    Boström, Henrik
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Maximizing the Area under the ROC Curve using Incremental Reduced Error Pruning2005In: Proceedings of the ICML 2005 Workshop on ROC Analysis in Machine Learning, Bonn: AMC Press , 2005Conference paper (Refereed)
  • 318.
    Boström, Henrik
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Maximizing the Area under the ROC Curve with Decision Lists and Rule Sets2007In: Proceedings of the 2007 SIAM International Conference on Data Mining, 2007, p. 27-34Conference paper (Refereed)
  • 319.
    Boström, Henrik
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Method for efficiently checking coverage of rules derived from a logical theory2008Patent (Other (popular science, discussion, etc.))
  • 320.
    Boström, Henrik
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Pruning and Exclusion Criteria for Unordered Incremental Reduced Error Pruning2004In: Proceedings of the Workshop on Advances in Rule Learning at 15th European Conference on Machine Learning, 2004Conference paper (Refereed)
  • 321. Boström, Henrik
    et al.
    Asker, Lars
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Gurung, Ram
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Karlsson, Isak
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Lindgren, Tony
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Papapetrou, Panagiotis
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Conformal prediction using random survival forests2017In: 16th IEEE International Conference on Machine Learning and Applications: Proceedings / [ed] Xuewen Chen, Bo Luo, Feng Luo, Vasile Palade, M. Arif Wani, Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 812-817Conference paper (Refereed)
    Abstract [en]

    Random survival forests constitute a robust approach to survival modeling, i.e., predicting the probability that an event will occur before or on a given point in time. Similar to most standard predictive models, no guarantee for the prediction error is provided for this model, which instead typically is empirically evaluated. Conformal prediction is a rather recent framework, which allows the error of a model to be determined by a user specified confidence level, something which is achieved by considering set rather than point predictions. The framework, which has been applied to some of the most popular classification and regression techniques, is here for the first time applied to survival modeling, through random survival forests. An empirical investigation is presented where the technique is evaluated on datasets from two real-world applications; predicting component failure in trucks using operational data and predicting survival and treatment of heart failure patients from administrative healthcare data. The experimental results show that the error levels indeed are very close to the provided confidence levels, as guaranteed by the conformal prediction framework, and that the error for predicting each outcome, i.e., event or no-event, can be controlled separately. The latter may, however, lead to less informative predictions, i.e., larger prediction sets, in case the class distribution is heavily imbalanced.

  • 322.
    Boström, Henrik
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Dalianis, Hercules
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    De-identifying health records by means of active learning2012In:  , 2012Conference paper (Refereed)
    Abstract [en]

    An experiment on classifying words in Swedish health records as belonging to one of eight protected health information (PHI) classes, or to the non-PHI class, by means of active learning has been conducted, in which three selection strategies were evaluated in conjunction with random forests; the commonly employed approach of choosing the most uncertain examples, choosing randomly, and choosing the most certain examples. Surprisingly, random selection outperformed choosing the most uncertain examples with respect to ten considered performance metrics. Moreover, choosing the most certain examples outperformed random selection with respect to nine out of ten metrics.

  • 323.
    Boström, Henrik
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Johansson, R.
    Karlsson, A.
    On Evidential Combination Rules for Ensemble Classifiers2008In: Proceedings of the 11th International Conference on Information Fusion, 2008Conference paper (Refereed)
  • 324.
    Boström, Henrik
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Knobbe, ArnoSoares, CarlosPapapetrou, PanagiotisStockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Advances in Intelligent Data Analysis XV: 15th International Symposium, IDA 2016, Stockholm, Sweden, October 13-15, 2016, Proceedings2016Conference proceedings (editor) (Refereed)
    Abstract [en]

    This book constitutes the refereed conference proceedings of the 15th International Conference on Intelligent Data Analysis, which was held in October 2016 in Stockholm, Sweden. The 36 revised full papers presented were carefully reviewed and selected from 75 submissions. The traditional focus of the IDA symposium series is on end-to-end intelligent support for data analysis. The symposium aims to provide a forum for inspiring research contributions that might be considered preliminary in other leading conferences and journals, but that have a potentially dramatic impact.

  • 325.
    Boström, Henrik
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Linusson, Henrik
    Lofstrom, Tuve
    Johansson, Ulf
    Accelerating difficulty estimation for conformal regression forests2017In: Annals of Mathematics and Artificial Intelligence, ISSN 1012-2443, E-ISSN 1573-7470, Vol. 81, no 1-2, p. 125-144Article in journal (Refereed)
    Abstract [en]

    The conformal prediction framework allows for specifying the probability of making incorrect predictions by a user-provided confidence level. In addition to a learning algorithm, the framework requires a real-valued function, called nonconformity measure, to be specified. The nonconformity measure does not affect the error rate, but the resulting efficiency, i.e., the size of output prediction regions, may vary substantially. A recent large-scale empirical evaluation of conformal regression approaches showed that using random forests as the learning algorithm together with a nonconformity measure based on out-of-bag errors normalized using a nearest-neighbor-based difficulty estimate, resulted in state-of-the-art performance with respect to efficiency. However, the nearest-neighbor procedure incurs a significant computational cost. In this study, a more straightforward nonconformity measure is investigated, where the difficulty estimate employed for normalization is based on the variance of the predictions made by the trees in a forest. A large-scale empirical evaluation is presented, showing that both the nearest-neighbor-based and the variance-based measures significantly outperform a standard (non-normalized) nonconformity measure, while no significant difference in efficiency between the two normalized approaches is observed. The evaluation moreover shows that the computational cost of the variance-based measure is several orders of magnitude lower than when employing the nearest-neighbor-based nonconformity measure. The use of out-of-bag instances for calibration does, however, result in nonconformity scores that are distributed differently from those obtained from test instances, questioning the validity of the approach. An adjustment of the variance-based measure is presented, which is shown to be valid and also to have a significant positive effect on the efficiency. For conformal regression forests, the variance-based nonconformity measure is hence a computationally efficient and theoretically well-founded alternative to the nearest-neighbor procedure.

  • 326.
    Boström, Henrik
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Linusson, Henrik
    Löfström, Tuve
    Johansson, Ulf
    Evaluation of a Variance-Based Nonconformity Measure for Regression Forests2016In: Conformal and Probabilistic Prediction with Applications: 5th International Symposium, COPA 2016, Madrid, Spain, April 20-22, 2016, Proceedings / [ed] Alexander Gammerman, Zhiyuan Luo, Jesús Vega, Vladimir Vovk, Springer, 2016, p. 75-89Conference paper (Refereed)
    Abstract [en]

    In a previous large-scale empirical evaluation of conformal regression approaches, random forests using out-of-bag instances for calibration together with a k-nearest neighbor-based nonconformity measure, was shown to obtain state-of-the-art performance with respect to efficiency, i.e., average size of prediction regions. However, the use of the nearest-neighbor procedure not only requires that all training data have to be retained in conjunction with the underlying model, but also that a significant computational overhead is incurred, during both training and testing. In this study, a more straightforward nonconformity measure is investigated, where the difficulty estimate employed for normalization is based on the variance of the predictions made by the trees in a forest. A large-scale empirical evaluation is presented, showing that both the nearest-neighbor-based and the variance-based measures significantly outperform a standard (non-normalized) nonconformity measure, while no significant difference in efficiency between the two normalized approaches is observed. Moreover, the evaluation shows that state-of-the-art performance is achieved by the variance-based measure at a computational cost that is several orders of magnitude lower than when employing the nearest-neighbor-based nonconformity measure.

  • 327. Botezatu, Mihaela
    et al.
    Hult, Håkan
    Kassaye Tessma, Mesfin
    Fors, Uno
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Virtual patient simulation for learning and assessment: superior results in comparison with regular course exams2010In: Medical Teacher, ISSN 0142-159X, Vol. 32, no 10, p. 845-850Article in journal (Refereed)
    Abstract [en]

    

    Background: Our study aimed to observe the differences in assessment results between virtual patient simulation (VPS) and regular course exams in an Internal Medicine course for undergraduate medical students.

    Methods: Four cohorts of students (n = 216) used: a VPS or lectures for learning (terms 1 and 2); VPS and lectures or only lectures (term 3); and a paired set-up with both VPS and lectures (term 4). The assessment results, measured with both a VPS-based exam and a paper-based exam, were compared. A scoring rubric (0–6), developed and validated for the purpose of the trial, was applied to both types of assessment. Mean score differences of the results were compared for the four cohorts.

    Results: Both VPS and regular examination results were significantly higher in the VPS group compared to regular exam group (p < 0.001) in terms 1, 2 and 3. The paired mean difference in term 4 was 0.66 (95% confidence interval (CI) 0.50, 0.83; p < 0.001) for haematology and 0.57 (95% CI 0.45, 0.69; p < 0.001) for cardiology.

    Conclusion: Our findings suggest that using VPS both for learning and for assessment supports learning. VPS are better than traditional assessment methods when the virtual application is used for both learning and evaluation.

  • 328. Botezatu, Mihaela
    et al.
    Hult, Håkan
    Kassaye Tessma, Mesfin
    Fors, Uno
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Virtual patient simulation: knowledge gain or knowledge loss?2010In: Medical Teacher, ISSN 0142-159X, Vol. 32, no 7, p. 562-568Article in journal (Refereed)
    Abstract [en]

    Background: Virtual patients (VPs), high-fidelity simulators and standardized patients are powerful educational interventions leading to effective learning and supporting knowledge retention.

    Aim: This study explored the variations in retention with VP versus regular learning activities.

    Method: We conducted a randomized controlled study on early and delayed assessment results of 49 students using VP for learning and examination of haematology and cardiology topics in an Internal Medicine course, by means of a 0–10 scoring rubric.

    Results: The mean difference for early assessment with VP (study – control mean score) was 1.43 (95% confidence interval (CI) 0.96, 1.91; p < 0.001) for haematology and 1.34 (95% CI 0.93, 1.76; p < 0.001) for cardiology. In regular exams, the mean score difference was 2.21 (95% CI 1.3, 3.1; p < 0.001) and 1.52 (95% CI 0.76, 2.28; p < 0.001), respectively. With delayed assessments, the difference in mean score for Web-SP was 1.48 (95% CI 1.09, 1.86; p < 0.001), haematology and 1.16 (95% CI 0.74, 1.58; p < 0.001), cardiology; for regular exams the figures were 1.96 (95% CI 0.93, 2.98; p < 0.001) and 1.74 (95% CI 0.89, 2.58; p < 0.001). The effect size ranged from 0.5 to 0.8.

    Conclusion: Our results indicate better retention with VP than with traditional learning methods.

  • 329. Botezatu, Mihaela
    et al.
    Hult, Håkan
    Tessma, Mesfin
    Dahlgren, Lars Owe
    Fors, Uno
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Virtual Patient Simulation: what do students make of it?: A focus group study2010In: BMC Medical Education, ISSN 1472-6920, E-ISSN 1472-6920, Vol. 10, no 91Article in journal (Refereed)
    Abstract [en]

    Background

    The learners' perspectives on Virtual Patient Simulation systems (VPS) are quintessential to their successful development and implementation. Focus group interviews were conducted in order to explore the opinions of medical students on the educational use of a VPS, the Web-based Simulation of Patients application (Web-SP).

    Methods

    Two focus group interviews-each with 8 undergraduate students who had used Web-SP cases for learning and/or assessment as part of their Internal Medicine curriculum in 2007-were performed at the Faculty of Medicine of Universidad el Bosque (Bogota), in January 2008. The interviews were conducted in Spanish, transcribed by the main researcher and translated into English. The resulting transcripts were independently coded by two authors, who also performed the content analysis. Each coder analyzed the data separately, arriving to categories and themes, whose final form was reached after a consensus discussion.

    Results

    Eighteen categories were identified and clustered into five main themes: learning, teaching, assessment, authenticity and implementation. In agreement with the literature, clinical reasoning development is envisaged by students to be the main scope of VPS use; transferable skills, retention enhancement and the importance of making mistakes are other categories circumscribed to this theme. VPS should enjoy a broad use across clinical specialties and support learning of topics not seen during clinical rotations; they are thought to have a regulatory effect at individual level, helping the students to plan their learning. The participants believe that assessment with VPS should be relevant for their future clinical practice; it is deemed to be qualitatively different from regular exams and to increase student motivation. The VPS design and content, the localization of the socio-cultural context, the realism of the cases, as well as the presence and quality of feedback are intrinsic features contributing to VPS authenticity.

    Conclusions

    Five main themes were found to be associated with successful VPS use in medical curriculum: Learning, Teaching, Assessment, Authenticity and Implementation. Medical students perceive Virtual Patients as important learning and assessment tools, fostering clinical reasoning, in preparation for the future clinical practice as young doctors. However, a number of issues regarding VPS design, authenticity and implementation need to be fulfilled, in order to reach the potential educational goals of such applications.

  • 330. Botezatu, Mihaela
    et al.
    Hult, Håkan
    Tessma, Mesfin
    Fors, Uno
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    As time goes by: stakeholder opinions on the implementation and use of a virtual patient simulation system2010In: Medical Teacher, ISSN 0142-159X (print), 1466-187X (electronic), Vol. 32, no 11, p. e509-516Article in journal (Refereed)
    Abstract [en]

    Background: Stakeholder opinions on the implementation of a particular virtual patient application might prove important for decision-making and implementation efforts in general. This study aimed to capitalize on experiences originated from two postimplementation settings of Web-based Simulation of Patients (Web-SP). Method: We conducted a cross-sectional survey of stakeholder opinions (39 students, teachers, course directors, and university leaders) on the implementation and use of Web-SP in Colombia and Sweden, using a mixed method approach. Results: The respondents did not show equal preference in rating the ranking of the order of importance included in the variables (Friedman’s Chi square: 26.5 to 115.1, df=6, p <0.001, Kendall’s coefficient of concordance ranging from 0.11 to 0.50). The answers provided as free comments supported the statistical findings on the importance of end-user customization, need for authenticity in software design, and use of virtual patient simulations in a curricular context, for clinical reasoning development. Conclusions: Virtual Patient design should allow extensive editing, support case authenticity and enhance clinical reasoning abilities, in an effort for ensuring accountability and sustainable development of the field.

  • 331.
    Brash, Danny
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Reuse in information systems development: a qualitative inquiry2002Doctoral thesis, monograph (Other academic)
  • 332. Bravos, George
    et al.
    Gonzalez Cardona, Tania
    Czubayko, Ulrich
    Donath, Janet
    España, Sergio
    Grabis, Janis
    Henkel, Martin
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Jokste, Lauma
    Kampars, Janis
    Kuhr, Jan-Christian
    Loucopoulos, Pericles
    Juanes Pascual, Raul
    Stirna, Janis
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Valverde, Francisco
    Zdravkovic, Jelena
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Deliverable 1.2: Initial version of requirements specification for CDD: CaaS - Capability as a Service in digital enterprises, Collaborative Project Number 6113512013Report (Other academic)
    Abstract [en]

    The CaaS project will elaborate the Capability Driven Development (CDD) approach that will allow digital enterprises to exploit the notion of 'capability' as a means of both designing for services and with services. This deliverable defines an initial set of requirements for CDD. These requirements are provided by the industrial partners through exploration of their use cases. The goal of this deliverable is to identify potential benefits that the CaaS approach could bring to the use cases as well the features to be included the CDD methodology. The requirements are elicited from the use case partners during semi-structured interviews. They are documented in a form of goal models, actor models and concept models for each partner separately. Information documented in these models is used to define envisioned capabilities to be design and delivered during the project as well as to establish the scope of each use case. The use case scope definition focuses on use case goals, causes of capability delivery variability, capability delivery context, functions to be provided in the use case as well as potential capability delivery adjustments. The use case specific models are combined together to obtain a preliminary set of general requirements for CDD. These requirements show CDD goals, types of stakeholders, types of context and types of adjustments. The deliverable ends with concluding remarks about the partners’ expectations for CDD. The requirements for the use cases described in this deliverable will be further elaborated in the final requirements document deliverable D1.4 and will be iteratively refined during the use case elaboration performed in work packages WP2, WP3 and WP4.

  • 333. Bravos, George
    et al.
    Grabis, Janis
    Henkel, Martin
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Jokste, Lauma
    Kampars, Janis
    Supporting Evolving Organizations: IS Development Methodology Goals2014In: Perspectives in Business Informatics Research: 13th International Conference, BIR 2014, Lund, Sweden, September 22-24, 2014. Proceedings / [ed] Björn Johansson, Bo Andersson, Nicklas Holmberg., Heidelberg: Springer , 2014, p. 158-171Conference paper (Refereed)
    Abstract [en]

    Organizations operate in increasingly dynamic and diverse environments. This leads to high variability within the organization, and the necessity to create context-aware information systems. As a part of these systems, context and business process metrics need to be monitored and acted upon. Capability Driven Development (CDD) addresses these challenges and integrates organizational development with IS (Information System) development. This paper integrates results from an industry survey and three industrial cases to define the key methodology goals for CDD.

  • 334. Brodin, Ulf
    et al.
    Fors, Uno
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Bolander Laksov, Klara
    The application of Item Response Theory on a teaching strategy profile questionnaire2010In: BMC Medical Education, ISSN 1472-6920, E-ISSN 1472-6920, Vol. 10, no 14Article in journal (Refereed)
    Abstract [en]

    Background

    In medical education research, various questionnaires are often used to study possible relationships between strategies and approaches to teaching and learning and the outcome of these. However, judging the applicability of such questionnaires or the interpretation of the results is not trivial.

    Methods

    As a way to develop teacher thinking, teaching strategy profiles were calculated for teachers in a research intensive department at Karolinska Institutet. This study compares the sum score, that was inherent in the questionnaire used, with an Item Response Theory (IRT) approach. Three teaching dimensions were investigated and the intended sum scores were investigated by IRT analysis.

    Results

    Agreements as well as important differences were found. The use of the sum score seemed to agree reasonably with an IRT approach for two of the dimensions, while the third dimension could not be identified neither by a the sum score, nor by an IRT approach, as the items included showed conflicting messages.

    Conclusions

    This study emphasizes the possibilities to gain better insight and more relevant interpretation of a questionnaire by use of IRT. A sum score approach should not be taken for granted. Its use has to be thoroughly evaluated.

  • 335. Bronäs, Agneta
    et al.
    Selander, StaffanStockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Verklighet, verklighet: teori och praktik i lärarutbildningen2015Collection (editor) (Other academic)
  • 336.
    Brouwers, Lisa
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Belastning på samhället vid ett utbrott av den nya pandmiska influensan A(H1N1) - preliminära resultat2009Other (Other (popular science, discussion, etc.))
  • 337.
    Brouwers, Lisa
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Fördelning av pandemivaccin mellan Sveriges landsting - simuleringsresultat2009Other (Other (popular science, discussion, etc.))
  • 338.
    Brouwers, Lisa
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    MicroPox: A Large-Scale and Spatially Explicit Microsimulation Model for Smallpox Planning2005In: The Proceedings of the 15th International Conference on Health Sciences Simulation / [ed] V. Ingalls, San Diego, Calif., 2005, p. 70-76Conference paper (Refereed)
  • 339.
    Brouwers, Lisa
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Microsimulation Models for Disaster Policy Making2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Two executable simulation models for answering policy questions were designed and implemented. The first for a flood management case, and the second for a disease transmission case that is currently underway. The flood simulation model differs from earlier natural disaster simulation models in several respects. It represents explicitly the geographical location and the economic strength of each household. It is also equipped with a graphical user interface, making it possible to design policies interactively, and to test their outcomes. If policy options are compared, the simulation results can automatically be transformed into decision trees. The flood simulation model shows that a micro-level representation makes it possible to investigate the distributional effects of policy changes. Novel features of the disease transmission model include the use of (anonymized) data representing nine million individuals, the inclusion of important parts of the contact patterns, and the explicit representation of places. The disease transmission model shows that the incorporation of social structure allows for a more realistic representation of disease spread than do models that assume homogenous mixing. Using this model, it is possible to conduct experiments of significant policy relevance, such as investigating the initial growth of an epidemic on a real-world network. Together, the two cases demonstrate the usefulness of a spatially explicit micro-level representation for policy simulation models in the area of disaster management.

  • 340.
    Brouwers, Lisa
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Microsimulation of Pandemic Influenza in Sweden2007Conference paper (Other academic)
  • 341.
    Brouwers, Lisa
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Spatial and Dynamic Modelling of Flood Management Policies in the Upper Tisza2003Report (Refereed)
    Abstract [en]

    Flood management policy has been the subject of an international joint research

    project with the Upper Tisza in Hungary as its pilot study area. Design specications

    for a geographically explicit simulation model are presented. Potential flood

    management policies, based on surveys and interviews with stakeholders, are presented.

    Some experiments on an executable prototype of the simulation model are

    also reported on, where the consequences of flood management policies are investigated.

    Focus has been on nancial policy measures, mainly insurance. Besides

    more traditional evaluation of policy scenarios, the model incorporates adaptive

    optimisation functionality. The report incorporates three contributions:

    1. the insurance policy issue in Hungary is framed in the broader context of flood

    management

    2. the structuring of a flood risk policy model, capable of simulating flood failures

    and estimating the economic consequences

    3. reports from policy experiments performed on the implemented prototype

    flood risk policy model

  • 342.
    Brouwers, Lisa
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Boman, Magnus
    Camitz, Martin
    Stockholm University, Faculty of Social Sciences, Department of Sociology.
    Mäkilä, Kalle
    Tegnell, Anders
    Micro-simulation of a smallpox outbreak using official register data2010In: Euro surveillance, ISSN 1025-496X, Vol. 15, no 35, p. 17-24Article in journal (Refereed)
    Abstract [en]

    To explore the efficacy of four vaccine-based policy strategies (ring vaccination, targeted vaccination, mass vaccination, and pre-vaccination of healthcare personnel combined with ring vaccination) for controlling smallpox outbreaks in Sweden, disease transmission on a spatially explicit social network was simulated. The mixing network was formed from high-coverage official register data of the entire Swedish population, building on the Swedish Total Population Register, the Swedish Employment Register, and the Geographic Database of Sweden. The largest reduction measured in the number of infections was achieved when combining ring vaccination with a pre-vaccination of healthcare personnel. In terms of per dose effectiveness, ring vaccination was by far the most effective strategy. The results can to some extent be adapted to other diseases and environments, including other countries, and the methods used can be analysed in their own right.

  • 343.
    Brouwers, Lisa
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Ekenberg, Love
    Hansson, Karin
    Danielson, Mats
    Multi-Criteria Decision-Making of Policy Strategies with Public-Private Re-Insurance Systems2004In: Risk Decision and Policy, Vol. 9, no 1, p. 23-45Article in journal (Refereed)
  • 344.
    Brouwers, Lisa
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Ekenberg, Love
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Hansson, Karin
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Danielson, Mats
    Örebro University, Örebro, Sweden.
    Multi-criteria decision-making of policy strategies with public-private re-insurance systems.2004In: Risk, Decision, and Policy, ISSN 1357-5309, E-ISSN 1466-4534, Vol. 9, no 1, p. 23-45Article in journal (Refereed)
    Abstract [en]

    This article describes an integrated flood catastrophe model as well as some results of a case study made in the Upper Tisza region in north-eastern Hungary: the Palad-Csecsei basin. The background data was provided through the Hungarian Academy of Sciences and complemented by interviews with different stakeholders in the region. Based on these data, for which a large degree of uncertainty is prevailing, we demonstrate how an implementation of a simulation and decision analytical model can provide insights into the effects of imposing different policy options for a flood risk management program in the region. We focus herein primarily on general options for designing a public-private insurance and reinsurance system for Hungary. Obviously, this is a multi-criteria and multi-stakeholder problem and cannot be solved using standard approaches. It should, however, be emphasised that the main purpose of this article is not to provide any definite recommendations, but rather to explore a set of policy packages that could gain a consensus among the stakeholders.

  • 345.
    Brouwers, Lisa
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Ekholm, Anders
    Janlöv, Nils
    Lindblom, Josepha
    Mossler, Karin
    Den ljusnande framtid är vård: delresultat från LEV-projektet2010Report (Other academic)
    Abstract [sv]

    År 2050 väntas andelen äldre i befolkningen öka från dagens 17 procent till 25 procent. Befolkningen åldras, hälsan förbättras och livslängden ökar. Det är en positiv utveckling som samhället måste anpassas till.

    Därför har en arbetsgrupp inom Socialdepartementet med en unik modell simulerat hur 300 000 individer åldras fram till 2050 och hur det väntas påverka hälsa, sjuklighet och dödlighet samt det framtida behovet av vård och omsorg. Simuleringarna visar att det är möjligt att kombinera åtgärder för att möta den åldrande befolkningens ökande behov av vård och omsorg om 10-15 år. Men det krävs ett målmedvetet arbete med att

    • förbättra hälsa och funktionsförmåga,
    • öka tillgängligheten,
    • få en effektiv vård och omsorg som tillämpar dagens kunskap och tänker nytt
    • forska och utveckla.
  • 346.
    Brouwers, Lisa
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Hansson, Karin
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    MicroWorlds as a Tool for Policy Making2001Conference paper (Refereed)
    Abstract [en]

    The Hungarian government is experiencing escalating costs for ood mitigation

    measures and for economical compensation to victims. In a joint

    research project between the International Institute of Applied System Analysis

    (IIASA) in Austria, Computer and System Science Department (DSV)

    in Sweden, and the Hungarian Academy of Science, the ooding problem of

    Upper Tisza in Hungary is investigated. A catastrophe simulation model has

    been implemented, where dierent policy options are tested and evaluated.

    We investigate how the willingness to buy insurance aects the results on

    the macro-level and on the micro-level.

  • 347.
    Brouwers, Lisa
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Hansson, Karin
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Ekenberg, Love
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Simulation of Three Competing Flood Management Strategies: A Case Study2002In: Applied Simulation and Modelling: Proceedings of the IASTED International Conference / [ed] L. Ubertini, Anaheim: Acta Press , 2002Conference paper (Refereed)
    Abstract [en]

    We argue that integrated catastrophe models are useful for policy decisions, for which a large degree of uncertainty is a natural ingredient. Recently, much attention has been given to the financial management of natural disasters. This article describes the results of a case study performed in northeastern Hungary where different flood management strategies have been explored and compared using an integrated catastrophe model. The area used for the pilot study is the Palad-Csecsei basin (the Pilot basin) where 4 621 persons live. The Pilot basin is located in the Upper Tisza region. An executable and geographically explicit model has been developed, linking hydrological, geographical, financial, and social data. The outcomes of the policy simulations are represented at different granularity-levels; the individual, the aggregated (entire basin), and the governmental.

  • 348.
    Brouwers, Lisa
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Hulth, Anette
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Nationell influensasammankomst 1-2 november 2007 - Sammanfattningar2007Other (Other (popular science, discussion, etc.))
  • 349.
    Brouwers, Lisa
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Liljeros, Fredrik
    The Functional Form of an Epidemic in a Real-World Contact NetworkManuscript (Other academic)
  • 350.
    Brouwers, Lisa
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Mäkilä, Kalle
    Camitz, Martin
    Spridning av smittkoppor - simuleringsexperiment2006Other (Other (popular science, discussion, etc.))
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