Introduction au logiciel R

The R software (R Core Development Team, 2012) is an open-source statistical software that allows data handling, statistical analyses and model fitting, , and graphical representations, among others. It is very flexible and has lots of pre-installed statistical methods. It is working under all operating systems, including Windows, Linux/UNIX and MacOS. The R community is worldwide and proposes free exchanges of shared R packages through the CRAN (comprehensive R archive network). However, the user needs some practice to become familiar with the software, as it does not have easy to use interface, yet. The purpose of this workshop is to illustrate some aspects of this software with applied purposes. A data set from the field of clinical psychology will be considered throughout the workshop as an illustrative example. Data loading in R, data manipulation, summary and simple statistics, graphics, basic (t-tests, ANOVA, …) and advanced (factor analysis, generalized linear modeling, item response theory, …) statistical analyses will be described and illustrated. Live demonstrations will be run and participants will be encouraged to practice during the workshop. Participants are required to bring their own laptops, preferably with R already installed (technical assistance will be provided before the workshop to help participants in installing R if necessary). The workshop will be mostly Windows users oriented. The illustrative data set will also be available for participants. Useful references and links: 1) The R software website: http://www.r-project.org 2) The Use R! series of Springer books in general, and more precisely: Zuur, A. F., Ieno, E. N., & Meesters, E. H. W. G. (2009). A beginner’s guide to R. New York: Springer