In this book, the authors argue that science concepts are more than what lecturers say and write on the board – science concepts cannot be abstracted from the complex performances that take place in the classroom. Through analysis of nonverbal aspects of communication and interaction during science lectures, which take into account the body, how it is placed in and moves across space, its orientation, its movements (gestures), the aspects of the setting it marks and other resources used, the authors show how each one of the resources employed provides different types and amounts of information that need to be taken into consideration all together, as a unit, to mark and re-mark sense so that audiences may remark it. The book also provides examples that show how the integration of multiple resources provides the coherence of the ideological unit, presenting lectures as an integrated performance of knowledge in action. The book is of interest for science educators and learning scientists in general, as well as scholars interested in multimodal analysis of interaction and face-to-face communication.