Rapid growth in public communication of science and technology has led to many diverse training programs. We ask: What are learning goals of science communication training? A comprehensive set of learning goals for future trainings will draw fully from the range of fields that contribute to science communication. Learning goals help decide what to count as success and how to gather evidence of learning. Based on the strands of learning developed for "learning science in informal environments", we built a conceptually coherent definition of science communication learning that addresses affective issues, content knowledge, methods, reflection, participation, and identity. We reviewed dozens of articles describing science communication training, identifying explicit and implicit learning goals. We identified gaps in outcomes commonly used for training programs; these gaps appeared especially in the areas of affective learning and identity formation. No one program can achieve all learning goals. Different courses might be tailored for scientists who remain in science, wish to become journalists, wish to work for museums, etc. But we believe conceptual coherence can help course designers identify important goals. Creating a common language will increase the ability to compare outcomes across courses and programs.