Dr. Mike Palmer, an Associate Professor of Botany at Oklahoma State University, put together this site as an instructional resource for a graduate-level course. Ordination, which means, literally, "the ordering of a set of data points with respect to one or more axes," is often used to generate hypotheses about the relationship between species composition and the underlying environmental gradients...
StatPrimer is "an online, public-domain biostatistics instructional manual." Biostatistics, in this case, can be somewhat misleading; the material covers many universal statistics concepts, but applies them to data sets and examples involving biology. Anyone wanting to learn about hypothesis testing, confidence intervals, regression, and several other statistical topics will find this site a...