Problem Statement: In recent years, researchers on learning have focused on learning with multimodal representation and this research has shown that when learners can interact with an appropriate representation their performance is enhanced. If students have the opportunity to interact consciously with modal representation, learning can be extended, comprehensively and deeply. This study studies the question of what would be the appropriate instructional design to scaffold such an enhancement and what would be the distribution of modes that would be found to be valuable, from students' perspective, in instruction and writing-to-learn activities, with specific regard to science education topics. Purpose of Study: The purpose of this study was two folded; firstly, to find out the effect of instructional activities on students' understanding of modal representations and, secondly, to explore the multimodal representations that college students find effective and use in studying some of the modern physics units. Methods: This study was carried out with 80 sophomore college students in Turkey within two identical sections of introductory modern physics for an education majors course in the 2007-2008 spring semester. Three assignments were designed and implemented to explore effective practices that can help students to enhance their understanding of modal representations. At the end of the instructional stage, through survey and semi-structured interviews, students were asked to evaluate the value of the instructional implementations and the effective modal representations in the learning of concepts. Findings and Results: Most of the students agreed that completing the three assignments was valuable in extending their understanding of modes; in understanding their roles in communicating ideas; in helping to scaffold their understanding, and effective usage, of modes and in increasing their knowledge with regard to modern physics units studied. In addition, students who participated in this study found the pictorial mode to be the most valuable in studying light, photo-electricity, and Compton effect units. On the other hand, students designated the textual mode as being the most valuable mode for studying the de Broglie unit. Moreover, students preferred to use picture and text in their writing-to-learn activity. Conclusions and Recommendations: An important theme emerges when the two parts of the results are considered. That is, when opportunities are provided to students in order to analyze and evaluate scientific materials from a multimodal perspective, they can build a concrete understanding of content knowledge as well as using modal representations to communicate ideas. Furthermore, if such opportunities are extended to create writing activities with multimodal representations, students additionally benefit by building content understanding and seeing what they know and do not know about the concept. When multimodal enriched learning opportunities are provided to college students to study introductory modern physics subjects, it appears that there is a mode cluster with picture and text becoming predominant. To promote the conceptual understanding of physics, we need not only to provide robust understanding of multimodal representations but also to be aware of modal clusters from multiple angles.