ABSTRACT
Human information processing often begins with the detection of an environmental event. This chapter will first deal with the signal detection situation in which an observer classifies the world into one of two states: signal present or absent. The detection process will be modeled within the framework of signal detection theory (SDT). This chapter will detail the role of sustained attention or vigilance in signal detection. The chapter then covers identification. We will present the simplest form of multilevel categorization, the absolute judgment task. We then examine the more complex multidimensional stimulus judgment. Finally, a supplement to this chapter presents the more technical details of information theory, which describes an alternative way of quantifying and modeling perceptual errors.
