Observation is widely regarded as a fundamental way of studying nature. However, due to its complexity, proposing a comprehensive characterization is challenging. Observation is a method of studying nature that can be divided into several dimensions. Each of these dimensions can be presented as a pair of terms, which are elaborated in this paper based on the epistemological, philosophical, and educational literature. In addition, the dimensions can be assigned to two levels, which can be used to group the individual dimensions. This epistemological perspective on the method is enriched by historical examples from different periods in physics and astronomy to substantiate and illustrate the classifications. The aim of the paper is to provide an overview of the epistemological features of the method in terms of these dimensions, which may be helpful for discussions in teacher training courses.