ABA is a scientific approach to understanding and changing human behavior. It is based on the principles of operant conditioning, which states that behavior is shaped by its consequences.

Operant conditioning is based on the principle that behavior is shaped by its consequences. This means that the likelihood of a behavior occurring again is increased if it is followed by a positive consequence, and decreased if it is followed by a negative consequence.

A reinforcer is a positive consequence that increases the likelihood of a behavior occurring again. Reinforcers can be tangible (e.g., food, money) or intangible (e.g., praise, attention).

A punisher is a negative consequence that decreases the likelihood of a behavior occurring again. Punishers can be physical (e.g., spanking, time-out) or psychological (e.g., criticism, disapproval).

The response is the behavior that is being increased or decreased. Responses can be overt (e.g., talking, walking) or covert (e.g., thinking, feeling).

A stimulus is an event or situation that triggers a behavior. Stimuli can be external (e.g., a loud noise) or internal (e.g., a thought or feeling).

Shaping is the process of gradually changing a behavior by reinforcing successive approximations of the desired behavior. This is done by starting with a behavior that is close to the desired behavior and gradually reinforcing closer and closer approximations until the desired behavior is achieved.

Chaining is the process of linking a series of behaviors together so that they occur in a specific order. This is done by reinforcing the completion of each behavior in the chain, and then gradually fading out the reinforcement for the earlier behaviors.

Fading is the process of gradually reducing the amount of support or assistance provided for a behavior. This is done by gradually decreasing the amount of reinforcement provided for the behavior, or by gradually increasing the difficulty of the task.

Prompting is the process of providing a cue or signal to help a person perform a behavior. Prompts can be physical (e.g., a hand-over-hand prompt), verbal (e.g., a verbal instruction), or visual (e.g., a picture).

Systematic desensitization is a procedure in which a person is exposed to a feared stimulus in a gradual and controlled manner. This is done by starting with a very low level of exposure and gradually increasing the intensity and duration of the exposure over time.

Flooding is a procedure in which a person is exposed to a feared stimulus all at once. This is done by exposing the person to the stimulus for a prolonged period of time, until the fear response habituates.

Cognitive-behavioral therapy is a procedure in which a person is taught to challenge and change their negative thoughts and beliefs. This is done by helping the person to identify their negative thoughts, evaluate the evidence for and against these thoughts, and develop more realistic and positive thoughts.

Progressive muscle relaxation is a procedure in which a person is taught to relax their muscles. This is done by tensing and then relaxing each muscle group in the body, starting with the feet and working up to the head.

Autogenic training is a procedure in which a person is taught to control their breathing. This is done by focusing on the breath and using mental imagery to create a state of relaxation.