Analysing count data – fitting and interpreting Generalised Linear Models (GLMs) (Kavita Isvaran): day4

Many questions in ecology and conservation science involve count data, such as the number of individuals of a species, the number of species (species richness), counts of behaviours performed by animals, counts of events such as crop damage, counts involving binary data (sex ratio, disease incidence, survival, mortality etc.) and so on. How do we analyse and make sense of such data? Regular linear models, like regression and ANOVA, do not perform well with count data. However, there is a class of powerful models, Generalised Linear Models (GLMs), that works very well with such data. GLMs are now commonly used to analyse count data in ecology and conservation science. In this workshop, we will focus on understanding, modelling and arriving at conclusions to questions in ecology and conservation science that involve count data. We will aim to (i) get an intuitive understanding of the sampling processes that generate count data; (ii) fit and interpret GLMs to count data; and (iii) discuss common pitfalls to analysing count data and ways to overcome them. This session will involve both discussions of the way these models work and hands-on experience in fitting and interpreting them using the software R.