In the early years of animal behavior studies, the most commonly used methodology was ad hoc observation, with the investigator picking and choosing the animals that seemed most interesting and then recording behavior that drew the investigator’s attention. This was adequate to gain basic natural history knowledge about species, but did not allow for testing hypotheses or for making quantitative comparisons. Rather late in the development of the field, Tinbergen framed his four questions. Only a decade after Tinbergen’s publication Altmann provided a roadmap for making systematic quantitative behavioral observations.
