In planning a terrestrial field study each component of the study should be considered in the context of all other components. There are close connections between the statement of the research question, the study design, the execution of the study, and the final conclusions. These components and their interrelationships are discussed in the context of field studies designed to evaluate effects of pesticides on avian species. Formulation of the research question and the design component are emphasized and attention is given to the topics of randomization, replication and error control. References for the application of these topics are provided.