Tuesday 25 August 2015

Time to event analysis (Survival analysis) in ecology

The August Eco-Stats Lab (Friday 28th, 2pm, Bioscience level 6) will be on time to event analysis in ecology.

When modelling the time taken for an event to happen (e.g.death) we often use time to event analysis (survival analysis) rather than regression models. A common feature of these data is that for some subjects the even did not happen at all during the study period, called (right) censoring, and survival analysis can elegantly incorporate the information from these subjects. Regression models on the other hand have no easy way to include these subjects.

Survival analysis can often be applied to ecological data, e.g.

- Arrival of a parasite

- Survival times for animals/plants 

- Germination timing

- Response to stimulus

- How long fruit remain on plants before they are eaten

We will use the survival package in R to analyse some ecological time to event data.  You can find the code/explanation here, and the data here.

Wednesday 19 August 2015

Workshop - Introduction to Regression Modelling on R, December 6-7

We will be running a two-day workshop at UNSW in the lead-up to the Eco-Stats conference in December.  This course is aimed at ecologists who recall some intro stats and want to get up to speed on more modern methods of modelling data using R.

The core idea in the course is to recognise that most statistical methods you use can be understood under a single framework, as special cases of (generalised) linear models - including linear regression, t-tests, ANOVA, ANCOVA, logistic regression and chi-square tests. Learning these methods in a systematic way, instead of as a "cookbook" of different methods, enables a systematic approach to key steps in analysis (like assumption checking) and extension to handle more complex situations you might encounter in the future (random factors, multivariate analysis, choosing between a set of competing models).

The course will be taught by the UNSW Eco-Stats group (it will be led by Francis Hui and Gordana Popovic, with contributions by David Warton and others).

Register via the conference website at http://www.eco-stats.unsw.edu.au/register.html