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Selecting the Response Form


Behavior analysis stresses the importance of a clear, measurable definition of what response will be targeted for reinforcement. We need to know precisely what we are teaching. If we are concerned about teaching children to develop communication, we must decide what communication behaviors will be shaped and strengthened through reinforcement. Remember that verbal behavior, like all other behaviors, will have certain characteristics that can be described in physical attributes such as which muscles are used in the behavior, how much force those muscles exert, when in time and space the movements occur, and so forth. Communication response forms such as vocal talk, sign language or use of a communication device, will differ significantly in the muscles used by the speaker as well as in other response dimensions including how easily they can be emitted (response effort). As teachers who are concerned about quality of life issues for students, we must select the response form for the student that will allow the greatest independence of performance and that will be understood by as many people who interact with the student as possible. We will also need to be concerned with how easy the response form is to use and, if we must shape a response form that is not vocal, how readily the form of communication can be transferred to vocal responses.


The first consideration when selecting a response form involves vocal responding. Given the fact that almost all speakers use a vocal response form and the ease at which vocal responses can be emitted in a fluent speaker, if at all possible a vocal response form should be selected for a student. However, for many children with autism and other disabilities, the acquisition of vocal responding is slowed or prohibited due to deficits in related skill areas. A child who fails to demonstrate any ability to echo what has been said or produces few spontaneous vocalizations will likely be less responsive to vocal training procedures. In such cases, it is important to implement procedures using an augmentative communication response system.


In order to select an augmentative communication system for a student, the instructional team will need to be aware of certain topics related to response form. Two general classes of response form in verbal behavior have been described (Michael, 1985). Those response classes are topographical and selection-based. A topographical response class involves responses that are discriminated by a listener based on distinguishable features of the response. In other words the acoustical features of the sound produced when one says “dog” will vary considerably from the acoustical patterns when one says “cat’. The topography (or dynamic movements) is clearly distinguishable. This is true for certain other response forms as well. Speakers of sign language produce clearly distinguishable movements for each unit of functional control. In other words the signs used to ask for a dog are quite different than the signs used to ask for a cat. The movements used in writing are also topographically distinct and result in distinct response products.


Another form of verbal behavior does not involve such clearly distinguished movements but yet provides stimuli that can be easily discriminated by a listener. A person can simply point to things in the environment in order to produce effects on the listener. The pointing shows little variation in the way it is emitted; rather the stimuli that are selected by the pointing are what lead to the listener’s differentiated response. When selection based verbal behavior occurs, the selection of a stimuli functions the same as the change of movement in topographical-based verbal behavior.


Chart 8

Topography Based Verbal BehaviorSelection Based Verbal Behavior
  • Vocal
  • Signing
  • Written
  • Picture exchange
  • Touch talkers and other devices
  • Communication board


There are benefits and disadvantages of all communication response forms. Each method of communicating has unique characteristics that make it more effective for specific circumstances. For instance, writing is helpful when verbal behavior needs to be recalled later. Voice activated devices will be helpful when the option of speaking with the vocal musculature is not possible.


One way of classifying verbal behavior is to look at the form the behavior takes and the environmental changes it generates. We may consider the behavior as the response form and the ensuing environmental change the response product. Such a classification of verbal behavior has been done by Patrick McGreevy (McGreevy, 2005).


The following chart reviews the relative advantages and disadvantages for the most frequently used communication response forms and is adapted from the work of Patrick McGreevy (2005).


Chart 9

Advantages and Disadvantages of Various Response Forms
 AdvantagesDisadvantages
Spoken Language
  • Most commonly used response form with wide community of skilled listeners
  • Free from environmental support: no materials or devices needed
  • Spoken language allows instruction across all verbal operants without confounds related to multiple control
  • Difficult to prompt oral/vocal motor movements
  • May be difficult to teach if the child does not have at least a minimum level of echoic repertoire (can begin repeating words or sounds)
Sign Language
  • Motor movements can be prompted and prompts faded
  • Signs often resemble what they communicate (iconicity)
  • Like speech, signing is a topographical system: each sign consists of distinct movements
  • Free from environmental support: no materials or devices needed
  • Sign language allows instruction across all verbal operants without confounds related to multiple control
  • Sign language is a language and has a community of speakers and listeners
  • Staff need specific training in sign language
  • There may be a limited community of natural speakers of sign language
  • Lack of a minimum level of motor imitation can hinder more rapid acquisition of signs
Picture Selection with an exchange
  • Scanning and pointing are the same for each verbal relation thus making response acquisition less complex
  • For picture exchange systems, contact between listener and speaker is more direct (requires some degree of physical proximity.)
  • Can be easily prompted
  • Does not require use of the vocal musculature system
  • May be more easily acquired with individuals who have significant motor skill deficits
  • Free from problems related to fidelity of sound production (i.e., articulation problems)
  • Requires extensive preparation of materials
  • Symbols and pictures become more abstract for advanced language
  • Requires user to carry materials therefore limiting situations and environments where it can be used
  • Communication becomes more difficult as language is acquired
  • Requires increasingly more complex visual discrimination skills
  • It may be difficult to discern operant control of responses: all responses involve match to sample and therefore tacts and intraverbals are not pure operants
  • Responding is relatively slow and limits the flow of communication
  • Complex response form required; user must scan and point while making a discrimination between the various visual stimuli
  • Communication is limited to the store of items available (if there isn’t a picture, the student can’t use that “word.”)
Picture Selection with voice output
  • These devices can be programmed to produce a full range of spoken communication
  • Scanning and pointing are the same for each verbal relation thus making response acquisition less complex
  • Can be easily prompted
  • Does not require use of the vocal musculature system
  • May be more easily acquired with individuals who have significant motor skill deficits
  • Voice activated devices must be programmed
  • Electronic devises may be prone to breaking or not working properly
  • Communication is limited to the store of items available (device must be programmed to allow full range of words student can use)
  • Skilled speakers must become technology savvy (must be able to navigate programs on device)
  • Complex response form required; user must scan and then point while also making a discrimination between the various visual stimuli available
  • Responding is slow and limits the natural flow of communication
  • Requires user to carry device therefore limiting situations and environments where it can be used
  • Requires increasingly more complex visual discrimination skills
Keyboarding
  • These devices can be programmed to produce a full range of written or, if voice activated, spoken communication
  • Does not require use of the vocal musculature system
  • Allows production of novel responses that do not require specific programming
  • Requires skilled keyboarding skills (refined motor movements)
  • Response is slow compared to signing and spoken and limits the natural flow of communication
  • Electronic devises may be prone to breaking or not working properly
  • Requires user to carry device therefore limiting situations and environments where it can be used
  • Requires increasingly more complex visual discrimination skills


Awareness of the relative advantages and disadvantages of various augmentative communication systems assists instructors in the process of selecting a response form for specific students.


Considerations When Making Decisions in Selecting a Response Form

  • The unique set of skills of the learner.
    The particular pattern of skill acquisition demonstrated by a student may be most easily identified through an analysis of a verbal behavior assessment protocol. Appropriate verbal behavior assessments include the Assessment of Basic Language and Learning Skills (Partington, 2007, Partington and Sundberg, 1998) and the Verbal Behavior Milestones Assessment and Placement Program (Sundberg, unpublished manuscript)
  • The ease of use for the various response forms
  • The degree to which the system allows development of a full range of verbal responses.
  • The availability of instructional procedures to facilitate acquisition of verbal responses

Here are some suggested guidelines for selecting a response form outlined by Dr. Vincent Carbone (Carbone, 2005);

  • If echoic skills are moderate or at least weak, then vocal behavior should be the response form of choice
  • If skilled attempts to teach a student an echoic repertoire are unsuccessful and the student is unable to mand or tact, then an augmentative response form should be considered.
  • If a student has a physical disability or a neurological disability which makes the differential muscle control necessary for signing impossible, a pointing or selection based system should be immediately considered.
  • If a student is young without physical conditions which preclude sign, then begin an intensive signing program that includes speaking while signing. The teacher will need to be skilled in prompting and differentially reinforcing vocalizations that may occur. The main reason for using sign immediately is that signs may lead to vocalizations more effectively than a selection based system.
  • For older students who may be involved in frequent community activities and who do not have a strong echoic repertoire or frequent verbalizations, a combination of signing and pointing systems may be best.
  • With older students signing should be taught because sign language will probably be acquired more quickly and will occur more easily across most environments and therefore may serve as a replacement for maladaptive (problem) behavior more quickly an deficiently.
  • An older person may have a need to immediately be taught to verbally interact with people in the community who do not have sign language skills and therefore, the student might benefit from use of a picture selection system. In some cases, the picture selection system may be more easily acquired once sign language has been taught.

Dr. Carbone (2005) has also posited considerations regarding attempts to teach sign language:

  • Obtain a sign manual or CD or take a signing course in ASL.
  • Make sure that all people who interact regularly with the student are familiar with sign language
  • Teach the first signs as mands
  • Use teaching procedures that include the fading of physical and gestural prompts to teach signed mands.
  • Insure that the student has many opportunities to use signs for mands.
  • Data systems should be in place to count the frequency of signed mands and to record how many signed mands the student has acquired.
  • Sign language training will need to be used in conjunction with echoic training and other procedures for teaching vocal responses.
  • Signs will need to be taught across all the verbal operants.
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