Background: Our theoretical perspectives direct ourresearch processes. The article contributes to the debateon Cultural Historical Activity Theory (CHAT) andDewey’s idea-based social constructivism, and to thedebate on methodology and how the researcher’s theoreticalstance guides the researcher in his or her work.Purpose: The article presents fundamental ideaswithin CHAT and Dewey’s idea-based social constructivism.The purpose of the text is to discuss and examinehow ideas in these two theories guide educationalresearch conducted within the framework of these twoapproaches. Furthermore, the article aims to contributeto the discussion on CHAT and Dewey’s theory.Sources of evidence: Ideas based on Vygotsky’stheories, represented mainly by James Wertsch, MichaelCole, Barbara Rogoff and Yrjö Engeström, andDewey’s ideas, are examined and discussed in relationto educational research. Furthermore, statements madeby Mietinnen, Garrison and Rorty are taken into accountin the discussion on the two outlined theories.Main argument: When CHAT and Dewey’s theoryguide researchers in their work, they have to take thecontext or situation into consideration. Artefacts aretreated as part of this context, and therefore have to bea focal point of the research. In educational research theclassroom and the teacher are also central parts of thelearning environment or context. The teacher is the oneto form the learning environment in which the pupilsthink and act, and therefore, the teacher’s role in theclassroom is important. If researchers are to manage tofocus on pupils’ learning, they must direct their researchfocus both on the teacher as an organizer of the activitiesand on the collaborating and supporting processes between the teacher and the pupils, and between thepupils. This means that the research focus has to includeboth activity and dialogue, which includes processes inall their complexity.Conclusions: Mediating artefacts play a central roleboth in CHAT and Dewey’s theory. If the researcher isto ascertain what the pupils learn when using specificartefacts, he or she will have to study the activities orprocesses within which these learning aids are used.This indicates that the researcher has to study learningprocesses in progress. Garrison states that Dewey’s approachis a philosophy of cultural development. Miettinenfinds that Dewey’s theory does not serve as thefoundation for both historical and cultural analyses ofaction. I disagree with Rorty and Mietinnen, and ratherfollow Garrison’s lead. In both theories, social, culturaland historical factors are, in my opinion, viewed asdecisive factors intertwined in what happens here andnow. Therefore the setting that frames the activity withits social, cultural and historical aspects also has to bebrought into focus in one’s research activity.