The aims of the present studies were to test the generalizability of the modality and dialogue effect to open learning environments, previously found by Moreno and Mayer (e.g., Moreno, Mayer & Lester, 2001) with an agent providing metacognitive support. As an extension, the agent's continuous presence effect on learning was also tested. Three studies were conducted. In all studies participants interacted with an open learning environment on an ecological problem. No confirmation was found for the modality or dialogue effect, nor did the agent's presence have any effect on students' performance. (Contains 1 table and 2 figures.)