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Journal ArticleDOI

Verification, Validation, and Confirmation of Numerical Models in the Earth Sciences

04 Feb 1994-Science (American Association for the Advancement of Science)-Vol. 263, Iss: 5147, pp 641-646
TL;DR: Verification and validation of numerical models of natural systems is impossible because natural systems are never closed and because model results are always nonunique.
Abstract: Verification and validation of numerical models of natural systems is impossible. This is because natural systems are never closed and because model results are always nonunique. Models can be confirmed by the demonstration of agreement between observation and prediction, but confirmation is inherently partial. Complete confirmation is logically precluded by the fallacy of affirming the consequent and by incomplete access to natural phenomena. Models can only be evaluated in relative terms, and their predictive value is always open to question. The primary value of models is heuristic.
Citations
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Journal ArticleDOI
TL;DR: A review of predictive habitat distribution modeling is presented, which shows that a wide array of models has been developed to cover aspects as diverse as biogeography, conservation biology, climate change research, and habitat or species management.

6,748 citations


Cites background or methods from "Verification, Validation, and Confi..."

  • ...verification, calibration, evaluation (= validation), qualification) have been covered in more specific papers, with very special attention given in recent years to evaluation and its usefulness for testing ecological models (e.g. Loehle, 1983; Oreskes et al., 1994; Rykiel, 1996)....

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  • ...…development (e.g. verification, calibration, evaluation (= validation), qualification) have been covered in more specific papers, with very special attention given in recent years to evaluation and its usefulness for testing ecological models (e.g. Loehle, 1983; Oreskes et al., 1994; Rykiel, 1996)....

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  • ...Loehle (1983), Oreskes et al. (1994) and Rykiel (1996) discuss the use of the term 6alidation when measuring the adequacy between model predictions and field observations, what is called accuracy assessment in remote sensing studies....

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  • ...To analyze the predictive success of models, we propose to follow Oreskes et al. (1994) and use the term e6aluation....

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  • ...However, saying that a model is ‘good’ or ‘bad’ is subject to critics, because it is implicit in modeling that perfect truth cannot be attained (Oreskes et al., 1994)....

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Journal ArticleDOI
TL;DR: In this paper, a numerical model for rock is proposed in which the rock is represented by a dense packing of non-uniform-sized circular or spherical particles that are bonded together at their contact points and whose mechanical behavior is simulated by the distinct element method using the two-and three-dimensional discontinuum programs PFC2D and PFC3D.

3,470 citations


Cites methods from "Verification, Validation, and Confi..."

  • ...No model is complete or fully verifiable [54], but the validity of the BPM is demonstrated by comparing model behavior with measured and observed responses of Lac du Bonnet granite at both laboratory and field scales in this and the next section....

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Journal ArticleDOI
TL;DR: The area under the receiver operating characteristic (ROC) curve, known as the AUC, is currently considered to be the standard method to assess the accuracy of predictive distribution models as discussed by the authors.
Abstract: The area under the receiver operating characteristic (ROC) curve, known as the AUC, is currently considered to be the standard method to assess the accuracy of predictive distribution models. It avoids the supposed subjectivity in the threshold selection process, when continuous probability derived scores are converted to a binary presence‐absence variable, by summarizing overall model performance over all possible thresholds. In this manuscript we review some of the features of this measure and bring into question its reliability as a comparative measure of accuracy between model results. We do not recommend using AUC for five reasons: (1) it ignores the predicted probability values and the goodness-of-fit of the model; (2) it summarises the test performance over regions of the ROC space in which one would rarely operate; (3) it weights omission and commission errors equally; (4) it does not give information about the spatial distribution of model errors; and, most importantly, (5) the total extent to which models are carried out highly influences the rate of well-predicted absences and the AUC scores.

2,711 citations


Cites background or methods from "Verification, Validation, and Confi..."

  • ...This paper was supported by a Fundación BBVA project (Diseño de una red de reservas para la protección de la Biodiversidad en América Austral), and two MEC Projects (CGL2004-04309 and CGL2006-09567/BOS)....

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  • ...Strictly speaking, only closed models can be validated (Oreskes et al ., 1994)....

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Journal ArticleDOI
TL;DR: A review of recent developments of LCA methods, focusing on some areas where there has been an intense methodological development during the last years, and some of the emerging issues.

2,683 citations


Cites background from "Verification, Validation, and Confi..."

  • ...To Oreskes et al. (1994) and Heijungs (2001), the only possible validation is the piecemeal one: unit processes, steps in impact pathways, etc., each building block may be validated separately, and as long as the gluing together proceeds according to strict procedures and mathematical rules, we can…...

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Journal ArticleDOI
TL;DR: In this paper, the authors review emerging ways to link theory to observation, and conclude that although, field observations can provide hints of alternative stable states, experiments and models are essential for a good diagnosis.
Abstract: Occasionally, surprisingly large shifts occur in ecosystems. Theory suggests that such shifts can be attributed to alternative stable states. Verifying this diagnosis is important because it implies a radically different view on management options, and on the potential effects of global change on such ecosystems. For instance, it implies that gradual changes in temperature or other factors might have little effect until a threshold is reached at which a large shift occurs that might be difficult to reverse. Strategies to assess whether alternative stable states are present are now converging in fields as disparate as desertification, limnology, oceanography and climatology. Here, we review emerging ways to link theory to observation, and conclude that although, field observations can provide hints of alternative stable states, experiments and models are essential for a good diagnosis.

2,464 citations

References
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Book
01 Jan 1934
TL;DR: The Open Society and Its Enemies as discussed by the authors is regarded as one of Popper's most enduring books and contains insights and arguments that demand to be read to this day, as well as many of the ideas in the book.
Abstract: Described by the philosopher A.J. Ayer as a work of 'great originality and power', this book revolutionized contemporary thinking on science and knowledge. Ideas such as the now legendary doctrine of 'falsificationism' electrified the scientific community, influencing even working scientists, as well as post-war philosophy. This astonishing work ranks alongside The Open Society and Its Enemies as one of Popper's most enduring books and contains insights and arguments that demand to be read to this day.

7,904 citations

Book
01 Jan 1980
TL;DR: In this book van Fraassen develops an alternative to scientific realism by constructing and evaluating three mutually reinforcing theories.
Abstract: In this book van Fraassen develops an alternative to scientific realism by constructing and evaluating three mutually reinforcing theories.

3,468 citations

Journal ArticleDOI
TL;DR: The distinction between normal and revolutionary science hold water as mentioned in this papereyerabend, T. S. Kuhn and T. E. Toulmin have made a distinction between the two categories of science.
Abstract: Preface Note on the third impression 1. Logic of discovery of psychology of research? T. S. Kuhn 2. Against 'Normal Science' J. W. N. Watkins 3. Does the distinction between normal and revolutionary science hold water? S. E. Toulmin 4. Normal science, scientific revolutions and the history of science L. Pearce Williams 5. Normal science and its dangers K. R. Popper 6. The nature of a paradigm Margaret Masterman 7. Falsification and the methodology of scientific research programmes I. Lakatos 8. Consolations for the specialist P. K. Feyerabend 9. Reflections on my critics T. S. Kuhn Index.

3,434 citations

01 Jan 1980

3,226 citations

Trending Questions (1)
Why is scholarly knowledge verification important to the academic community?

Scholarly knowledge verification is important to the academic community because it establishes the legitimacy and reliability of research findings.