the behavior is less likely to occur in the presence of the stimulus. In a similar manner, the removal of a stimulus directly following the behavior might either increase or decrease the frequency of that behavior in the future (negative reinforcement or punishment). For instance, a student that gained praise and a good grade after turning in a paper, might seem more motivated in writing papers in the future (positive reinforcement); if the same student put in a lot of work on a task without getting any praise for it, he or she might seem less motivated to do school work in the future (negative punishment). If a student starts to cause trouble in the class gets punished with something he or she dislikes, such as detention (positive punishment), that behavior would decrease in the future. The student might seem more motivated to behave in class, presumably in order to avoid further detention (negative reinforcement). The strength of reinforcement or punishment is dependent on schedule and timing. A reinforcer or punisher affects the future frequency of a behavior most strongly if it occurs within seconds of the behavior. A behavior that is reinforced intermittently, at unpredictable intervals, will be more robust and persistent, compared to the ones that are reinforced every time the behavior is performed. For example, if the misbehaving student in the above example was punished a week after the troublesome behavior, that might not affect future behavior. In addition to these basic principles, environmental stimuli also affect behavior. Behavior is punished or reinforced in the context of whatever stimuli were present just before the behavior was performed, which means that a particular behavior might not be affected in every environmental context, or situation, after it is punished or reinforced in one specific context. A lack of praise for school-related behavior might, for instance, not decrease after-school sports-related behavior that is usually reinforced by praise. The various mechanisms of operant conditioning may be used to understand the motivation for various behaviors by examining what happens just after the behavior (the consequence), in what context the behavior is performed or not performed (the antecedent), and under what circumstances (motivating operators). Incentive motivation Incentive theory is a specific theory of motivation, derived partly from behaviorist principles of reinforcement, which concerns an incentive or motive to do something. The most common incentive would be a compensation. Compensation can be tangible or