Applied behavior analysis

# Overview
Applied behavior analysis (ABA) is the science of applying experimentally derived principles of behavior to improve socially significant behavior. ABA takes what we know about behavior and uses it to bring about positive change (Applied). Behaviors are defined in observable and measurable terms in order to assess change over time (Behavior). The behavior is analyzed within the environment to determine what factors are influencing the behavior (Analysis). Applied behavior is the third of the four domains of behavior analysis, the other three being, behaviorism, experimental analysis of behavior and professional practice of behavior analysis.
Applied behavior analysis contributes to a full range of areas including: AIDS prevention, conservation of natural resources, education, gerontology, health and exercise, industrial safety, language acquisition, littering, medical procedures, parenting, seatbelt use, sports, and zoo management and care of animals.
ABA-based interventions have gained recent popularity in the last 20 years related to teaching students with autism spectrum disorders.

# Definition
ABA is defined as the science in which tactics derived from the principles of behavior are applied systematically to improve socially significant behavior and experimentation is used to identify the variables responsible for change.
Baer, Wolfe, and Risley's 1968 article is still used as the standard description of ABA. and it describes the seven dimensions of ABA; application, a focus on behavior, the use of analysis, a technological approach, conceptually systematic, effective, and generality.

## Characteristics
Baer, Wolf, and Risley's seven dimensions:
- Applied: ABA focuses on areas that are of social significance.  In doing this, behavior scientists must take into consideration more than just the short-term behavior change, but also look at how behavior changes can affect the consumer, those who are close to the consumer, and how any change will affect the interactions between the two.
- Behavioral: ABA must be behavioral, i.e.: behavior itself must change, not just what the consumer SAYS about the behavior. It is not the goal of the behavior scientists to get their consumers to stop complaining about behavior problems, but rather to change the problem behavior itself.  In addition, behavior must be objectively measured.  A behavior scientist can not resort to the measurement of non-behavioral substitutes.
- Analytic: The behavior scientist can demonstrate believable control over the behavior that is being changed. In the lab, this has been easy as the researcher can start and stop the behavior at will. However, in the applied situation, this is not always as easy, nor ethical, to do. According to Baer, Wolf, and Risley, this difficulty should not stop a science from upholding the strength of its principles. As such, they referred to two designs that are best used in applied settings to demonstrate control and maintain ethical standards. These are the reversal and multiple baseline designs. The reversal design is one in which the behavior of choice is measured prior to any intervention. Once the pattern appears stable, an intervention is introduced, and behavior is measured. If there is a change in behavior, measurement continues until the new pattern of behavior appears stable. Then, the intervention is removed, or reduced, and the behavior is measured to see if it changes again. If the behavior scientist truly has demonstrated control of the behavior with the intervention, the behavior of interest should change with intervention changes.
- Technological: This means that if any other researcher were to read the study's description, that researcher would be able to "replicate the application with the same results". This means that the description must be very detailed and clear. Ambiguous descriptions do not qualify.  Cooper et al. describe a good check for the technological characteristic: "have a person trained in applied behavior analysis carefully read the description and then act out the procedure in detail. If the person makes any mistakes, adds any operations, omits any steps, or has to ask any questions to clarify the written description then the description is not sufficiently technological and requires improvement."
- Conceptually Systematic: A defining characteristic is in regards to the interventions utilized; and thus research must be conceptually systematic by only utilizing procedures and interpreting results of these procedures in terms of the principles from which they were derived.
- Effective: An application of these techniques improve behavior under investigation.  Specifically, it is not a theoretical importance of the variable, but rather the practical importance (social importance) that is essential.
- Generality: It should last over time, in different environments, and spread to other behaviors not directly treated by the intervention.  In addition, continued change in specified behavior after intervention for that behavior has been withdrawn is also an example of generality.
In 2005, Heward, et al added the following four characteristics:
- Accountable: Direct and frequent measurement enables analysts to detect their success and failures to make changes in an effort to increase successes while decreasing failures.   ABA is a scientific approach in which analysts may guess but then critically test ideas, rather than "guess and guess again".  this constant revision of techniques, commitment to effectiveness and analysis of results leads to an accountable science.
- Public: Applied behavior analysis is completely visible and public.  This means that there are no explanations that cannot be observed.  There are no mystical, metaphysical explanations, hidden treatment, or magic
- Empowering: ABA provides tools to practitioners that allow them to effectively change behavior.  By constantly providing visual feedback to the practitioner on the results of the intervention, this feature of ABA allows clinicians to assess their skill level and builds confidence in their technology.
- Optimistic: According to several leading authors, practitioners skilled in behavior analysis have genuine cause to be optimistic for the following reasons:
- The environmental view is essentially optimistic as it suggests that all individuals possess roughly equal potential
- Direct and continuous measurements enable practitioners to detect small improvements in performance that might have otherwise been missed
- As a practitioner uses behavioral techniques with positive outcomes, the more they will become optimistic about future success prospects
- The literature provides many examples of success teaching individuals considered previously unteachable.

# Concepts

## Behavior
Behavior is the activity of living organisms. Human behavior is the entire gamut of what people do including thinking and feeling.  Behavior can be determined by applying the Dead Man's test:
"If a dead man can do it, it ain't behavior.  And if a dead man can't do it, then it is behavior"
Often, the term behavior is used to reference a larger class of responses that share physical dimensions or function.  In this instance, the term response indicates a single instance of that behavior.  If a group of responses have the same function, this group can be classified as a response class.  Finally, when discussing a person's collection of behavior, repertoire is used.  It can either pertain specifically to a set of response classes that are relevant to a particular situation, or it can refer to every behavior that a person can do.

### Operant conditioning
Operant behavior is that which is selected by its consequences. The conditioning of operant behavior is the result of reinforcement and punishment.  Operant behavior is produced primarily by striated muscles and sometimes by smooth muscles and glands

### Respondent conditioning
All organisms respond in predictable ways to certain stimuli.  These stimulus-response relations are called reflexes.  The response component of the reflex is called respondent behavior.  It is defined as behavior which is elicited by antecedent stimuli.  Respondent conditioning (also called Classical Conditioning) is learning in which new stimuli acquire the ability to elicit respondents.  This is done through stimulus-stimulus pairing, for example, the stimulus (smell of food) can elicit a person's salivation.  By pairing that stimulus (smell) with another stimulus (word "food"), the second stimulus can obtain the function

## Environment
The environment is the entire constellation of circumstances in which an organism exists.   This includes events both inside and outside of an organism, but only real physical events are included.  The environment is comprised of stimuli.  A stimulus is an "energy change that affects an organism through its receptor cells."
A stimulus can be described:

## Reinforcement
Reinforcement is the most important principle of behavior and a key element of most behavior change programs.  It is the process by which behavior is strengthened, if a behavior is followed closely in time by a stimulus and this results in an increase in the future frequency of that behavior.  The addition of a stimulus following an event that serves as a reinforcer is termed positive reinforcement.  If the removal of an event serves as a reinforcer, this is termed negative reinforcement.  There are multiple schedules of reinforcement that effect the future frequency of behavior.  Extinction is a schedule of reinforcement in which no reinforcer follows a behavior and results in a decline in future frequency of behaviors.

## Punishment
Punishment is a process by which a consequence immediately follows a behavior which decreases the future frequency of that behavior.  Like reinforcement, a stimulus can be added (positive punishment) or removed (negative punishment).  Broadly, there are three types of punishment: presentation of aversive stimuli, response cost and time out.  Punishment in practice can often result in unwanted side effects, and has as such been used only after reinforcement-only procedures have failed to work.  Unwanted side effects can include the increase in other unwanted behavior as well as a decrease in desired behaviors.  Some other potential unwanted effects include escape and avoidance, emotional behavior, and can result in behavioral contrast.

## Discriminated operant and three-term contingency
In addition to a relation being made between behavior and its consequences, operant conditioning also establishes relations between antecedent conditions and behaviors.  This differs from the S-R formulations (If-A-then-B), and replaces it with an AB-because-of-C formulation.  In other words, the relation between a behavior(B) and its context(A) is because of consequences (C), more specifically, this relationship between AB because of C indicates that the relationship is established by prior consequences that have occurred in similar contexts.  This antecedent-behavior-consequence contingency is termed the three term contingency. 
A behavior which occurs more frequently in the presence of an antecedent condition than in its absence is called a discriminated operant.  The antecedent stimulus is called a discriminative stimulus SD.  The fact that the discriminated operant occurs only in the presence of the discriminative stimulus is an illustration of stimulus control.

# Measuring behavior
When measuring behavior, there are both dimensions of behavior and quantifiable measures of behavior.  In applied behavior analysis, the quantifiable measures are a derivative of the dimensions.  These dimensions are repeatability, temporal extent, and temporal locus.

## Repeatability
Response classes occur repeatedly throughout time -- ie how many times the behavior occurs.
- Count is the number of occurrences in behavior.
- Rate/Frequency is the number of instances of behavior per unit of time.
- Celeration is the measure of how the rate changes over time.

## Temporal extent
This dimension indicates that each instance of behavior occupies some amount of time -- ie how long the behavior occurs.
- Duration is the amount of time in which the behavior occurs.

## Temporal locus
Each instance of behavior occurs at a specific point in time -- ie when the behavior occurs.
- Response latency is the measure of elapsed time between the onset of a stimulus and the initiation of the response.
- Interresponse time is the amount of time that occurs between two consecutive instances of a response class.

## Derivative measures
Derivative measures are unrelated to specific dimensions:
- Percentage is the ratio formed by combining the same dimensional quantities.
- Trials-to-criterion measurement of the number of response opportunities needed to achieve a predetermined level of performance.

# Analyzing behavior change

## Experimental control
In applied behavior analysis, all experiments should include the following:
- At least one participant
- At least one behavior (dependent variable)
- At least one setting
- A system for measuring the behavior and ongoing visual analysis of data
- At least one treatment or intervention condition
- Manipulations of the independent variable so that its effects on the dependent variable

# Functional Behavior Assessment (FBA)
Functional assessment of behavior provides hypotheses about the relationships between specific environmental events and behaviors. Decades of research has established that both desirable and undesirable behaviors are learned through interactions with the social and physical environment. FBA is used to identify the type and source of reinforcement for challenging behaviors as the basis for intervention efforts designed to decrease the occurrence of these behaviors.

## Functions of behavior
The function of a behavior can be thought of as the purpose a behavior serves for a person. Function is identified in an FBA by identifying the type and source if reinforcement for the behavior of interest.  Those reinforcers might be positive or negative social reinforcers provided by someone who interacts with the person, or automatic reinforcers produced directly by the behavior itself.
- Positive Reinforcement - social positive reinforcement (attention), tangible reinforcement, and automatic positive reinforcement.
- Negative Reinforcement - social negative reinforcement (escape), automatic negative reinforcement.

### Function versus topography
Behaviors may look different but can serve the same function and likewise behavior that looks the same may serve multiple functions. What the behavior looks like often reveals little useful information about the conditions that account for it. However, identifying the conditions that account for a behavior, suggests what conditions need to be altered to change the behavior. Therefore, assessment of function of a behavior can yield useful information with respect to intervention strategies that are likely to be effective.

## FBA methods
FBA methods can be classified into three types:
- Functional (experimental) Analysis
- Descriptive Assessment
- Indirect Assessment

### Functional (experimental) analysis
A functional analysis is one in which antecedents and consequences are manipulated to indicate their separate effects on the behavior of interest.  This type of arrangement is often called analog because they are not conducted in a naturally occurring context.  However, research is indicating that functional analysis done in a natural environment will yield similar or better results
A functional analysis normally has four conditions (three test conditions and one control):
- Contingent attention
- Contingent escape
- Alone
- Control condition
Advantages - it has the ability to yield a clear demonstration of the variable(s)that relate to the occurrence of a problem behavior.  Serves as the standard of scientific evidence by which other assessment alternative are evaluated, and represents the method most often used in research on the assessment and treatment of problem behavior.
Limitations - assessment process may temporarily strengthen or increase the undesirable behavior to unacceptable levels or result in the behavior acquiring new functions. Some behaviors may not be amenable to functional analysis (e.g. those that, albeit serious, occur infrequently). Functional analysis conducted in contrived settings may not detect the variable that accounts for the occurrence in the natural environment.

### Indirect FBA
This method uses structured interviews, checklists, rating scales, or questionnaires to obtain information from persons who are familiar with the person exhibiting the behavior to identify possible conditions or events in the natural environment that correlate with the problem behavior.  They are called "indirect" because they do not involve direct observation of the behavior, but rather solicit information based on others' recollections of the behavior.
- Advantages - some can provide a useful source of information in guiding subsequent, more objective assessments, and contribute to the development of hypotheses about variable that might occasion or maintain the behaviors of concern.
- Limitations - informants may not have accurate and unbiased recall of behavior and the conditions under which it occurred.

### Descriptive FBA
As with Functional Analysis, descriptive functional behavior assessment utilizes direct observation of behavior; unlike functional analysis, however, observations are made under naturally occurring conditions.  Therefore, descriptive assessments involve observation of the problem behavior in relation to events that are not arranged in a systematic manner.
There are three variations of descriptive assessment:
- ABC (antecedent-behavior-consequence) continuous recording - observer records occurrences of targeted behavior and seelected environmental events in the natural routine.
- ABC narrative recording - data are collected only when behaviors of interest are observes, and the recording encompasses any events that immediately precede and follow the target behavior.
- Scatterplots -a procedure for recording the extent to which a target behavior occurs more often at particular times than others.

## Conducting an FBA
Provided the strengths and limitations of the different FBA procedures, FBA can best be viewed as a four-step process:

# Technologies discovered through ABA research

## Task analysis
Task analysis is a process in which a task is analyzed into its component parts so that those parts can be taught through the use of chaining: forward chaining, backward chaining and total task presentation. Task analysis has been used in organizational behavior management, a behavior analytic approach to changing organizations.  Behavioral scripts often emerge from a task analysis. Bergan conducted a task analysis of the behavioral consultation relationship and Thomas Kratochwill developed a training program based on teaching Bergan's skills.  A similar approach was used for the development of microskills training for counselors. Ivey would later call this "behaviorist" phase a very productive one and the skills-based approach came to dominate counselor training during 197090. Task analysis was also used in determining the skills needed to access a career.  In education, Englemann (1968) used task analysis as part of the methods to design the Direct Instruction curriculum.

## Chaining
The skill to be learned is broken down into  small units for easy learning. For example, a person learning to brush teeth independently may start with learning to unscrew the toothpaste cap. Once the he or she has learned this, the next step may be squeezing the tube, etc.
For problem behavior chains can also be analyzed and the chain can be disrupted to prevent the problem behavior. Some behavior therapies, such as Dialectical Behavior Therapy, make extensive use of behavior chain analysis.

## Prompting
A prompt is a cue or assistance to encourage the desired response from an individual. Prompts are often categorized into a prompt hierarchy from most intrusive to least intrusive. There is some controversy about what is considered most intrusive: physically intrusive versus hardest prompt to fade (ie. verbal). In an errorless learning approach, prompts are given in a most-to-least sequence and faded systematically to ensure the individual experiences a high level of success. There may be instances in which a least-to-most prompt method is preferred.  Prompts are faded systematically and as quickly as possible to avoid prompt dependency. The goal of teaching using prompts would be to fade prompts towards independence, so that no prompts are needed for the individual to perform the desired behavior.
Types of prompts:
- Verbal prompts: Utilizing a vocalization to indicate the desired response.
- Visual Prompts: a visual cue or picture.
- Gestural prompts: Utilizing a physical gesture to indicate the desired response.
- Positional prompt: The target item is placed closer to the individual.
- Modeling: Modeling the desired response for the student. This type of prompt is best suited for individuals who learn through imitation and can attend to a model.
- Physical prompts: Physically manipulating the individual to produce the desired response.  There are many degrees of physical prompts. The most intrusive being hand-over-hand, and the least intrusive being a slight tap to initiate movement.
This is not an exhaustive list of all possible prompts.  When using prompts to systematically teach a skill, not all prompts need to be used in the hierarchy; prompts are chosen based on which ones are most effective for a particular individual.

## Fading
The overall goal is for an individual to eventually not need prompts. As an individual gains mastery of a skill at a particular prompt level, the prompt is faded to a less intrusive prompt. This ensures that the individual does not become overly dependent on a particular prompt when learning a new behaviour or skill.

## Thinning
Thinning is often confused with fading. Fading refers to a prompt being removed, where thinning refers to the spacing of a reinforcement schedule getting larger. Some support exists that a 30% decrease in reinforcement can be an efficient way to thin. Schedule thinning is often an important and neglected issue in contingency management and token economy systems, especially when developed by unqualified practitioners (see professional practice of behavior analysis).

## Generalization
Generalization is the expansion of a student's performance ability beyond the initial conditions set for acquisition of a skill. Generalization can occur across people, places, and materials used for teaching. For example, once a skill is learned in one setting, with a particular instructor, and with specific materials, the skill is taught in more general settings with more variation from the initial acquisition phase. For example, if a student has successfully mastered learning colors at the table, the teacher may take the student around the house or his school and then generalize the skill in these more natural environments with other materials. Behavior analysts have spent considerable amount of time studying factors that lead to generalization.

## Shaping
Shaping involves gradually modifying the existing behavior into the desired behavior. If the student engages with a dog by hitting it, then he or she could have their behavior shaped by reinforcing interactions in which he or she touches the dog more gently.  Over many interactions, successful shaping would replace the hitting behavior with patting or other gentler behavior. Shaping is based on a behavior analyst's thorough knowledge of operant conditioning principles and Extinction (psychology). Recent efforts to teach shaping have used simulated computer tasks.

## Video modeling
One teaching technique found to be effective with some students, particularly children, is the use of video modeling (the use of taped sequences as exemplars of behavior).  It can be used by therapists to assist in the acquisition of both verbal and motor responses, in some cases for long chains of behavior.

## Interventions based on an FBA
Critical to behavior analytic interventions is the concept of a systematic behavioral case formulation with a functional behavioral assessment or analysis at the core.  This approach should apply a behavior analytic theory of change (see behavioural change theories).  This formulation should include a thorough functional assessment, a skills assessment, a sequential analysis (behavior chain analysis),an ecological assessment, a look at existing evidenced-based behavioral models for the problem behavior (such as Fordyce's model of chronic pain) and then a treatment plan based on how environmental factors influence behavior. Some argue that behavior analytic case formulation can be improved with an assessment of rules and rule governed behavior. Some of the interventions that result from this type of conceptualization involve training specific communication skills to replace the problems behavior as well as specific setting, antecedent, behavior, and consequece strategies.