Book excerpt: Eye witness testimony, training, driving, and display design: these are just a few of the real-world domains in which depend on undivided attention. Emphasizing the link between theory and application, Applied Attention Theory provides a deep understanding of how theories of attention, developed from laboratory-based psychological research, can inform our understanding of everyday human performance in a wide number of applications and environments. The basic theories discussed concern divided, focused, and selective attention, and areas of application include mental workload measurement, multi-tasking, distracted driving, complex display design, education, and the training of attentional skills.