Archive for plagiarism

R [re-]exam

Posted in Books, R, Statistics, University life with tags , , , , on March 28, 2011 by xi'an

In what seems like an endless cuRse, I found this week I had to re-grade a dozen R exams a TA’s did not grade properly! The grades I (X) got are plotted below against those of my TA (Y). There is little connection between both gradings… As if this was not enough trouble, I also found exactly duplicated R codes in another R project around Introducing Monte Carlo methods with R that was returned a few weeks ago. Meaning I will have to draft a second round exam… (As Tom commented on an earlier post, team resolution of a given problem may be a positive attitude, but in the current case one student provided an A⁺⁺ answer, while two others clearly drafted an hasty resolution from the original.) Nonetheless, do not worry, I still love [teaching] R!

Top ten on HAL

Posted in Statistics, University life with tags , , on June 24, 2010 by xi'an

I was updating my entries on HAL from my arXives and found this top ten ranking of my papers:

  1. Sélection bayésienne de variables en régression linéaire, with A. Guillin and J.-M. Marin  inria-00077857
  2. Adaptive Importance Sampling in General Mixture Classes, with O. Cappé, R. Douc, A. Guillin and J.-M. Marin inria-00181474/hal-00180669
  3. A Bayesian reassessment of nearest-neighbour classification, with L. Cucala, J.-M. Marin and D.M. Titterington inria-00143783
  4. Deviance Information Criteria for Missing Data Model, with G. Celeux, F. Forbes and D.M. Titterington inria-00071724
  5. Minimum variance importance sampling via Population Monte Carlo, with R. Douc, A. Guillin and J.-M. Marin inria-00070316
  6. Computational and Inferential Difficulties with Mixture Posterior Distributions, with J.-M. Marin inria-00073049
  7. Are risk averse agents more optimistic? A Bayesian estimation approach, with S. Benmansour, E. Jouini, C. Napp and J.-M. Marin  halshs-00163678
  8. Convergence of adaptive sampling schemes, with R. Douc, A. Guillin and J.-M. Marin inria-00070522
  9. Brownian Confidence Bands on Monte Carlo Output, with W. Kendall and J.-M. Marin inria-00070571
  10. Iterated importance sampling in missing data problems, with G. Celeux and J.-M. Marin inria-00070473

Nothing much to comment except that those are only recent papers (obviously, since HAL also is a recent creation), a large majority of which revolve around population Monte Carlo (and almost all co-authored with Jean-Michel Marin!). The #9 with WIlfrid Kendall and Jean-Michel Marin is clearly very popular as someone attempted to plagiarise it! The #1 comes as a real surprise, given that it is in French and more of a survey.

plagiarism exposed!

Posted in R, Statistics, University life with tags , , , , , on June 15, 2010 by xi'an

Last morn, I had the surprise of receiving the following email:

This is to inform you that the following abstract has been submitted to the 3rd International Conference of the ERCIM WG on COMPUTING & STATISTICS (ERCIM’10)

Ab#: 114
Title: Goodness of Fit Via Mixtures of Beta distributions
Keywords: nonparametric estimation, posterior conditional predictive p-value.
Abstract: We consider a Bayesian approach to goodness of fit, that is, to the problem of testing whether or not a given parametric model is compatible with the data at hand . Since we are concerned with a goodness of fit problem, it is more of interest to consider a functional distance to the tested model d(F;F) as the basis of our test, rather than the corresponding Bayes factor, since the later puts more emphasis on the parameters. It is both of high interest and of strong difficulty to come up with a satisfactory notion of a Bayesian test for goodness ofit to a distribution or to a family of distributions.

The abstract is a plagiarism of your work.

I am informing you of about this in case the author has tried to plagiarize the whole paper. The same author has submitted a second abstract plagiarizing another paper.  The author uses bogus affiliations and I cannot trace his institution in case he has one.

It is somehow comforting to see that such a gross example of plagiarism can get detected, despite the fact that our paper never got published. Although I am sure there must be conferences that do not apply any filter on the submission…

This paper with Judith Rousseau was once submitted to Series B, but I could not come to complete the requested revision for programming motives, the task of modifying the several thousand lines of C code driving the beta mixture estimation filling me with paralysing dread! This is actually the time when I stopped programming in C (the fact that I ever really programmed in C is actually debatable!). This is unfortunate as the spirit of the paper was quite nice, using an idea borrowed from Verdinelli and Wasserman to build a genuine Bayesian goodness of fit test… I do not think there is much to salvage at this later stage, given the explosion of Bayesian non-parametrics.