Picture Exchange Communication System

The training protocol is based on the principles of applied behavior analysis. The goal of PECS is spontaneous and functional communication. The PECS teaching protocol is based on B. F. Skinner's book, Verbal Behavior, such that functional verbal operants are systematically taught using prompting and reinforcement strategies that will lead to independent communication. Verbal prompts are not used, thus building immediate initiation and avoiding prompt dependency. PECS begins with teaching a student to exchange a picture of a desired item with a communicative partner, who immediately honors the request. After the student learns to spontaneously request for a desired item, the system goes on to teach discrimination among symbols and then how to construct a simple sentence. In the most advanced phases, individuals are taught to respond to questions and to comment. Additionally, descriptive language concepts such as size, shape, color, number, etc. are also taught so the student can make their message more specific. For example, I want big yellow ball. ==PECS protocol==

Reinforcer inventory: Prior to implementing the PECS protocol, the teacher, parent, or caregiver develops an inventory of items such as toys, books, and edibles that the learner enjoys. Preferred items are presented to the learner to determine which one(s) they want. This preference assessment is completed throughout the day in a variety of activities. Once the desired item or activity is determined, the communicative partner will entice the student with the item. This way, no verbal prompting is needed. The PECS Protocol occurs in six phases: Phase 1 – how to communicate: During phase I, the focus is on teaching the student to initiate social communication by exchanging a picture of a desired item. and reach towards the communicative partner with the picture, in exchange for the requested item. Phase 2 – distance and persistence: During phase 2, the student is taught to expand the initiated social interaction by creating motivation for the student to seek out the communicative partner even when he or she is not nearby and waiting. Phase 4 – using phrases: Within phase 4, the student learns to construct simple sentences on a detachable sentence strip, making requests such as "I want ____ ". The requests consist of a sentence starter, "I want", and a picture of the desired activity or item. The communicative partner reads back the sentence after it has been exchanged by the student. After the student has learned to construct the sentence and point to the pictures, a delay between "I want" and the picture of the desired item is inserted as a way to encourage vocalizations. Speech/vocalizations are celebrated by providing the student with a greater amount of the requested item/activity and additional preferred items as a way to promote speech on future exchanges. Speech/vocalizations are never demanded, just encouraged through the use of the delay. Teaching PECS users to create a sentence using expressions such as "I want ___" is the first step in developing more complex sentence structures. After the student learns the basic sentence structure, descriptors such as color, shape, size, and number are taught so that learner can make their preferences more specific, such as "I want 3 cars". Depending on the age and cognitive level of the user, the time to master PECS will vary. One study found that it takes an average of 246 trials for users to master all six phases of PECS. ==Effectiveness==

A 2011 meta-analysis found no statistically significant difference in the efficacy of PECS when comparing autistic and non-autistic study participants and when comparing those taught in single or multiple settings. The meta-analysis also stated it may be necessary to adapt PECS to accommodate learners with visual impairments, fine or gross motor difficulties, or problems discriminating between picture symbols. While the authors stated that the case studies they analyzed generally supported the use of PECS to foster communication, they qualified that more research was necessary to validate its effectiveness beyond its third phase, its effectiveness in promoting speech, its effectiveness when used across different settings, and its effectiveness when administered by non-researchers. A 2008 meta-analysis of existing research found that PECS was effective in improving the functional communication skills of autistic individuals, but recommended further research be conducted on individuals with other diagnoses. An initial concern was that PECS might delay or inhibit speech development. However, a 2010 review of several peer-reviewed studies found that "there is no evidence within the reviewed studies to suggest that PECS inhibited speech; to the contrary, if any effect was observed, it was facilitative rather than inhibitory." A systematic review of interventions for autistic children reported that use of PECS resulted in short-term improvement in word acquisition, but the effects were not maintained over time. A 2012 meta-analysis suggested that PECS may be more effective for children who have difficulty sustaining joint attention. A 2010 meta-analysis found mixed evidence that PECS improves aspects of functional communication related to maintenance and generalization. A 2008 meta-analysis stated, "PECS is probably best used as an initial intervention to teach requesting and the basic elements of what is a communicative exchange." The meta-analysis further concluded that PECS was not well suited for longterm use, "as it does not address question asking and may be better implemented as part of a multimodal system for when picture communications are more socially appropriate." ==See also==