Abstract. Previous research seems to support the assumption that students need instructional guidance to activate and correct their preconceptions. Such an instructional strategy is the CONTACT strategy, characterised by continuous, computer-assisted activation of the conceptions of individual learners. Our previous study showed that the CONTACT strategy was effective in promoting conceptual change in text processing (domain: physical geography) because students (fifth-and sixth-graders, primary education) constructed more correct conceptions. However, students mainly seemed to focus on the central concepts from the training texts, disregarding other information. Therefore, the strategy was adapted to solve this problem of selective attention and to increase its effectiveness. Subjects (74 fifth-and sixth-graders) were assigned to three instructional conditions (original CONTACT condition, revised CONTACT-2 condition and control condition NO ACTIVATION). A mixed between-within-subjects design was used with 2 between-subjects factors (instructional condition and students' familiarity with the central concepts from the 7 texts used). Dependent variables concerned quality of conceptions and learning performance. Students from the CONTACT-2 condition constructed better conceptions and achieved higher learning performance scores than students from the other two conditions. Moreover, the effectiveness of the CONTACT-2 strategy appeared not to depend on the degree of conceptual resemblance between the performance test questions and the central concepts from the texts and on the moment of testing. Additional research should shed some light on the instructional conditions required to teach students how they themselves can initiate and perform learning activities aimed at conceptual change.