The purpose of this study is to describe in detail how communication technologies facilitate or hinder communication between nurses and physicians with the ultimate goal of identifying the optimal ways to support effective communication. Communication failures between physicians and nurses are one of the most common causes of adverse events for hospitalized patients as well as a major root cause of all sentinel events. Communication technology (i.e., the electronic medical record, computerized provider order entry, email, and pagers), created through health information technology (HIT), may help reduce some communication failures but increase others because of an inadequate understanding of how communication technology is used. Our theoretical model is based in communication and sociology theories to describe how communication technologies affect communication through communication practices (i.e., use of rich media; the location and availability of computers) and work relationships (i.e., hierarchies and team stability). Specific Aims: We seek to: (1) identify the range of communication technologies used in a national sample of medical-surgical acute care units; (2) describe communication practices and work relationships that may be influenced by communication technologies in these same settings; and (3) explore how differences in communication technologies, communication practices, and work relationships between physicians and nurses influence communication. Design and Methods: This study will use a sequential mixed methods design, beginning with a quantitative survey followed by a two-part qualitative phase. Survey results from Aim 1 will provide a detailed assessment of communication technologies in use (important for meeting meaningful use criteria) and help identify sites with variation in communication technologies for the qualitative phase of the study. In Aim 2 we will conduct telephone interviews with hospital personnel in up to 8 hospitals to gather in depth information about communication practices and work relationships on medical-surgical units. In Aim 3 we will collect data in 4 hospitals (selected from telephone interview results) via observation, shadowing, focus groups, and artifacts to learn how communication technologies, communication practices, and work relationships affect communication. Significance: Current communication technologies are based on models of individual decision-making and may not be sufficient for, or may interfere with, decisions requiring input from multiple perspectives. Complex one-of-a-kind problems, such as those frequently encountered in hospital settings, require knowledge building as part of the problem solution, which current communication technologies do not facilitate. As the majority of American hospitals do not yet have HIT fully implemented results from our study may inform future development and implementation of communication technologies.