The research methods on teacher's thinking, restricted by the tools and technique, mostly collect data from the idea that "language is the tool of thinking", and then explore how thinking is produced through the analysis of language. However, researchers must notice that semantics are not equal to meaning which made by mind activities. Researchers need to understand how the meaning of language is formed in the mind and its context. In research ontology subject is the study that deals with how the origins of events are formed reasonably without defining the thinking by predetermined theories. In research Epistemology subject is the study that associates with the elimination of dualism of mind and body, focusing on the formation of subject and object. This article believes that Heussrl's intentionality will bring inspiration on research methodology, ontology and epistemology.