When teachers or instructors create computer-based learning environments, they often solely consider technical aspects of interactivity. As a consequence, learners’ main role is to respond to requests of the learning environment (e.g. by answering multiple-choice questions). This aspect of interactivity is, however, not sufficient to understand the complex benefits of interactivity for learners’ knowledge acquisition. In order to create a higher level of interactivity, an instructional task that encourages learners to design learning materials for fellow learners is used in this paper. We will show that this instructional task can induce interactive elements because learners are encouraged to take not only their own perspective into account when designing. In addition, we investigated if the quality of source material affects knowledge acquisition in design tasks. In a two-by-two design, students (n = 108) had to design either a learning environment for others (i.e. to perform perspective-shifting), or a representation of acquired knowledge for themselves (no perspective-shifting) with less or more coherent information sources. Results indicate that performing perspective-shifting can be a powerful technique for eliciting interactive learning behavior and, thus, for learning. The quality of information sources does not influence knowledge acquisition to a great extent.