A relationship philosophy-science education is illustrated by a case study. Based in a phenomenological approach, experimental activity in science is shown as a space which establishes a close and dynamic relationship between the construction of phenomenologies and development of formalization and conceptual processes. It is clarified first what it is understood by the terms: phenomenon and phenomenology, as well as experience, experiment, and experimentation. Then it is shown the way this perspective is concreted in the particular case of the study of the qualities of acidity and alkalinity of substances and the formulation of pH.