Computer software is an essential tool for many statistical modelling and data analysis techniques, aiding in the implementation of large data sets in order to obtain useful results. R is one of the most powerful and flexible statistical software packages available, and enables the user to apply a wide variety of statistical methods ranging from simple regression to generalized linear modelling. 'Statistics - an introduction using R' is a clear and concise introductory textbook to statistical analysis using this powerful and free software. Features step-by-step instructions that assume no mathematics, statistics or programming background, helping the non-statistician to fully understand the methodology. Uses a series of realistic examples, developing step-wise from the simplest cases, with the emphasis on checking the assumptions and the adequacy of the model chosen to fit the data. The emphasis throughout is on estimation of effect sizes and confidence intervals, rather than on hypothesis testing. Covers the full range of statistical techniques likely to be needed to analyse the data from research projects, including elementary material like t-tests and chi-squared tests, intermediate methods like regression and analysis of variance, and more advanced techniques like generalized linear modelling.