Communication in learning systems not only involves structured content but affect and empathy to assist the delivery of meaning and to sustain engagement. In multimodal presentations gestures can be used to reinforce these attributes and provide semantic integration of the visual and verbal modalities. We report on comparative studies between different presentation formats employing gestures, and their influence on learning comprehension. In contrast, for online multimodal simulations, computing systems have to take more active and knowledgeable roles to support interactions in ways that provide an adaptive framework for engagement and reflective discussion. A simulation project directed at decision making skills is used to focus on these design issues.