Mayer's SOI theory suggests that supplements added to designed environments can promote learners' knowledge construction and that different types of supplements will serve different purposes in knowledge construction. Some adjuncts can facilitate selection. Other adjuncts, such as diagrams, might facilitate the organization of important information because they require the learner to see relationships not readily apparent in the text. Yet other adjuncts, such as animation, might facilitate the integration of important information within the supplement and with prior knowledge and therefore assist learners' knowledge integration. This study addressed the effects of two different types of inserted supplements in to-be-learned web-based instructional materials. In accord with SOI theory, one type, factual questions, is designed to promote learners' selection of important information. The other, elaborative interrogation, is designed to facilitate deeper processing through integration of the to-be-learned information and prior knowledge. In summary, then, the current work examined the use of inserted questions designed to focus learners' attention or deeper-level processing.