Smith and Kirby (2000) argue for a two-process model of appraisal, which expands on the function of the structural model of appraisal. While the structural model of appraisal focuses on what one is evaluating, the process model of appraisal focuses on how one evaluates emotional stimuli. There are three main components to the process model of appraisal: perceptual stimuli, associative processing, and reasoning. Perceptual stimuli are what the individual picks up from his or her surroundings, such as sensations of pain or pleasure, perception of facial expression (Smith & Kirby 2000). In addition to these stimuli, the process model is composed to two main appraisal processes. Associative processing is a memory-based process that makes quick connections and provides appraisal information based on activated memories that are quickly associated with the given stimulus (Marsella & Gratch 2009). Reasoning is a slower, more deliberate, and thorough process that involves logical, critical thinking about the stimulus and/or situation (Marsella & Gratch 2009). In the two-process model of appraisal theory, associative processing and reasoning work in parallel in reaction to perceptual stimuli, thus providing a more complex and cognitively based appraisal of the emotional encounter (Smith & Kirby 2000).