Stats for Everyone

In #science #statistics #probability #sie #books

Have a statistics question or project? I'd love to hear from you! One of my goals is to bring statistical reasoning to everyone, both as a general framework for rational thinking but also for specific uses in the arts and sciences. I wrote a book, which I post for free but is also available on Amazon, which presents a unique path through an introductory statistics class. I also write tools to help researchers apply statistical techniques to their data and their problems.

The Book - for free!

Tools

  • Quantity.py

    A simple class for doing Monte Carlo error analysis

Presentations

Publications

  • Witkowski, C. R., Weijers, J. W. H. , Blais, B.S., Schouten, S., and Damsté, J. S. S. Molecular fossils from phytoplankton reveal secular pCO$_2$ trend over the Phanerozoic. Science Advances. Vol. 4, no. 11, eaat4556. DOI: 10.1126/sciadv.aat4556.

  • Skaza, J. and Blais, B.S. 2013. The Relationship between Economic Growth and Environmental Degradation: Exploring Models and Questioning the Existence of an Environmental Kuznets Curve . Available from: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2346173 and http://intranet.bryant.edu/portal/economic-studies/publications/working-papers.htm.

    In this paper, we explore a variety of models attempting to explain the pollution-income relationship (PIR). There has been much literature addressing the notion of an environmental Kuznets curve (EKC). Many researchers find an EKC relationship for certain pollutants, while others do not find evidence of an EKC relationship. There is also literature formally critiquing the EKC. We employ cross-sectional, panel, and time-series analysis to add insight into the relationship between economic growth and environmental degradation, a research area that is far from consensual and that has practical implications. We ultimately find that the clearest case of an EKC effect in our study arises in the analysis of organic water pollution, while there is modest evidence suggesting an EKC effect with regard to CO2, NO, and methane. We also present ample evidence suggesting an anti-EKC effect for PM10. Our analysis causes us to question the existence of an EKC effect throughout the environment in general.

  • Yang, H., Blais, B.S., Leng, Q. 2011. Stable isotope variations from cultivated Metasequoia trees in the United States: A statistical approach to assess isotope signatures as climate signals. Jpn. J. His tor. Bot. 19 (1-2) pp 75-88.

    We measured I'C and I'15N values and carbon and nitrogen elemental concentrations of leaves collected from Metasequoia glyptostroboides Hu et Cheng trees cultivated at 39 sites across the United States under different latitudes and climatic regions. I'D values from south facing leaf n-alkanes of 27 trees were also determined. Climate data over the past 50 years (1950a2009) were compiled from stations near each site. Isotope data were cross plotted against each geographic and climatic parameter, including latitude, annual mean temperature (AMT), spring (FebruaryaMay) mean temperature (SMT), annual mean precipitation (AMP), and spring mean precipitation (SMP). Statistical analyses revealed the following signicant correlations: 1) a strong negative correlation between n-alkane D and latitude; 2) statistically signicant correlations between D and both AMT and SMT; 3) a weaker but still signicant correlation between I'D and SMP; 4) statistically signicant relationships between carbon concentration and both temperature and precipitation parameters, especially AMP; 5) an unexpected correlation between nitrogen concentration and SMP. These results bear strong implications for using I'13C and I'D values obtained from fossil Metasequoia as paleoclimatic and paleoenvironmental proxies.

  • Kuindersma, S.R. and Blais, B.S. 2007. Teaching Bayesian Model Comparison With the Three-sided Coin . American Statistician. Vol. 61, No. 3, August 2007 pp.239-244

    In the present work we introduce the problem of determining the probability that a rotating and bouncing cylinder (i.e. flipped coin) will land and come to rest on its edge. We present this problem and analysis as a practical, nontrivial example to introduce the reader to Bayesian model comparison. Several models are presented, each of which take into consideration different physical aspects of the problem and the relative effects on the edge landing probability. The Bayesian formulation of model comparison is then used to compare the models and their predictive agreement with data from hand-flipped cylinders of several sizes.