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Articles avec #statistique - modelisation - plans experimentaux

Pour en savoir un peu plus sur Excel

22 Novembre 2015,

Publié par Bioécologie

Excelabo vous propose gratuitement près de 1500 pages de tutoriels et d'astuces consacrées à Excel et au Visual Basic for Applications, 600 classeurs exemples dont le code est accessible, pour vous permettre de découvrir ce puissant logiciel, d'en apprendre les bases et de progresser dans la conception et la maîtrise de vos propres outils.

Pour en savoir un peu plus sur Excel

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10 Novembre 2015,

Publié par Bioécologie

Is it a fixed or random effect?

9 Novembre 2015,

Publié par Bioécologie

Posted on November 2015 by Brian McGill

Teaching a graduate statistics class, I end up as a statistical consultant a lot. One of the questions I get most often is should I treat this as a fixed or a random effect? This topic seems to be shrouded in mystery. Indeed when I came of age statistically in the dark ages (=20 years ago), the main distinction given between a fixed and a random effect was philosophically based: are you measuring a few specific instances of interest in themselves (=fixed) or a few randomly chosen instances interesting only as representatives of a population (=random). This is not a bad approach, and seems clear to me, although I have to confess I have not had great luck teaching this distinction.

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Is it a fixed or random effect?

Beyond Bar and Line Graphs: Time for a New Data Presentation Paradigm

9 Novembre 2015,

Publié par Bioécologie

Weissgerber TL, Milic NM, Winham SJ, Garovic VD (2015) Beyond Bar and Line Graphs: Time for a New Data Presentation Paradigm. PLoS Biol 13(4): e1002128. doi:10.1371/journal.pbio.1002128

Abstract

Figures in scientific publications are critically important because they often show the data supporting key findings. Our systematic review of research articles published in top physiology journals (n = 703) suggests that, as scientists, we urgently need to change our practices for presenting continuous data in small sample size studies. Papers rarely included scatterplots, box plots, and histograms that allow readers to critically evaluate continuous data. Most papers presented continuous data in bar and line graphs. This is problematic, as many different data distributions can lead to the same bar or line graph. The full data may suggest different conclusions from the summary statistics. We recommend training investigators in data presentation, encouraging a more complete presentation of data, and changing journal editorial policies. Investigators can quickly make univariate scatterplots for small sample size studies using our Excel templates.

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 Bar graphs and scatterplots convey very different information.
 Bar graphs and scatterplots convey very different information.

Bar graphs and scatterplots convey very different information.

Analysing mesocosm experiments using Generalized Linear Models

29 Juillet 2015,

Publié par Bioécologie

Author: Eduards Szöecs

"Based on 11 mesocosm data sets (thanks to the co-authors who kindly shared their data) I compared 3 different methods to analyse such data. In this post I show how to analyse mesocosm data using Generalized Linear Models for multivariate data."

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