The book is a reference tool to help experimental and field biologists define their hypotheses, design an appropriate experiment or mensurative study, translate it into a statistical model, analyse the data and validate the resulting output. As such, it is intended to be a companion throughout the scientific process. At the planning stage, the documented tables allow users to make informed choices about the design of experiments or fieldwork, with particular regard to the need for replication and the different scales of replication across space or over time. Different designs are directly comparable, facilitating the task of balancing costs of replication against benefits of predictive power and generality. At the analysis stage, the book shows how to construct ANOVA models with the correct F-ratios for testing the hypotheses, gives options for post hoc pooling of error terms, and highlights the assumptions underlying the predictions. Finally, by appreciating the methods used by computer packages to perform ANOVAs, users can check that their input model is appropriately structured and correctly formatted for the desired hypothesis, can verify that the output has tested the intended hypothesis with the correct error degrees of freedom, and can draw appropriate conclusions from the results.