Concepts and Principles
The contingency
Operant behavior is explained by motivating operation (MO) → discriminative stimulus (SD) → response → consequence. Reinforcement increases behavior; punishment decreases it. Positive means a stimulus is added; negative means one is removed. Know the 2×2 grid cold: positive reinforcement, negative reinforcement, positive punishment, negative punishment (response cost, time-out).
What to distinguish
- SD vs. MO. An SD signals availability and depends on a learning history; an MO alters the value of a consequence and the momentary frequency of behavior, with no history required. Rain is an MO for opening an umbrella; a dark sky is an SD.
- Escape vs. avoidance. Escape terminates an aversive stimulus already present; avoidance prevents one that is upcoming.
- MO types. Establishing operations increase value, abolishing operations decrease it; each may be unconditioned (deprivation, pain) or conditioned (CMO-R, CMO-T, CMO-S).
- Stimulus control. A flat generalization gradient indicates poor discrimination; generalization is a continuum, not a failure.
- Schedules. FR produces post-reinforcement pauses; VR produces high steady rates; FI produces scalloping.
Traps
Questions often describe a procedure and ask you to name it. Ask: did behavior increase or decrease, and was a stimulus added or removed? "The teacher took away the toy and hitting dropped" is negative punishment, not extinction - extinction means the reinforcer maintaining the behavior was withheld.
Worked example
A child screams until an adult hands over a tablet, and screaming increases. That is positive reinforcement maintained by a tangible contingency; the tablet's presence is an SD under an EO of tablet deprivation. If the adult said "no" and screaming dropped, the label would be punishment - but the stem must show a decrease to support it.