Content uploaded by Frank R. Rusch
Author content
All content in this area was uploaded by Frank R. Rusch on Jul 06, 2016
Content may be subject to copyright.
A Review and Analysis of the Picture
Exchange Communication System (PECS)
for Individuals With Autism Spectrum
Disorders Using a Paradigm of
Communication Competence
Cheryl Ostryn, Pamela S. Wolfe, and Frank R. Rusch
The Pennsylvania State University
Research related to the use of the Picture Exchange
Communication System (PECS) with individuals having
autism spectrum disorders (ASDs) was examined using a
communication competence paradigm detailed by J. C.
Light (1988, 1989, 2003). Communication components
were operationalized based on skills identified in ASD re-
search. A review was conducted to examine general PECS
outcomes and outcomes related to communication compe-
tence including generalized, spontaneous, and joint atten-
tion abilities, and maintenance. Results indicated that there
were few empirical studies related to the PECS. Of note,
the reported studies indicated generally positive outcomes
for individuals with ASDs, particularly related to manding
and generalization. When the communication competence
paradigm was applied, results indicated that, in its present
form, the PECS needs to be used as a part of a multimodal
communication system. Results suggest that training related
to the PECS includes joint attention and question asking.
Recommendations for the use of PECS andfuture research
with individuals having ASDs are outlined.
DESCRIPTORS: autism, AAC, Picture Exchange
Communication System
Communication can be characterized as the relaying
and receiving of information, needs, or thoughts in a
shared medium that has communicative intent to affect
the receiver’s behavior in some way (Bogdashina, 2005).
Individuals with autism spectrum disorders (ASDs) often
exhibit communication impairments and may have limi-
ted understanding of social cues, thereby resulting in be-
haviors that are difficult to positively reinforce (Bondy &
Frost, 1994; Frea, Arnold, & Vittimberga, 2001; Worth,
2005). Approximately 50% of children with ASDs do
not develop speech and language skills that are deemed
functionally adequate to meet their daily communica-
tion needs (Lord, Risi, & Pickles, 2004). Nonvocal indi-
viduals with ASDs can communicate using alternative and
augmentative communication (AAC) systems that can
encompass both aided and unaided systems. Aided com-
munication involves using objects, such as electronic vi-
sual display boxes, symbols, and pictures, whereas unaided
systems do not require external objects. Examples of un-
aided systems can include using one’s own hands for sign
language and gestures (Cafiero, 2005).
One method used to teach communication to indi-
viduals with ASDs using an aided AAC system is the
Picture Exchange Communication System (PECS) devel-
oped by Bondy and Frost (1994). The PECS has been
widely used with individuals with disabilities, particularly
individuals with ASDs (Anderson, Moore, & Bourne,
2007; Simpson et al., 2005). In the PECS, individuals ex-
change pictures of items to obtain tangibles and other
needs (Bondy & Frost, 2001). The PECS is comprised of
six phases to teach communication. The first phase of the
PECS uses instruction related to manding; individuals
make a request by exchanging a picture of a desired item
with a communicative partner and immediately receiving
the desired item. This first phase is expanded through
the remaining phases of instruction: increased distance,
picture discrimination, sentence construction, answering
questions, and commenting (Bondy & Frost, 2002). Each
of the PECS phases is to be mastered in sequence and
requires an 80% mastery level of spontaneous and
generalized communication attempts before progressing
to the next stage. The aim of the PECS is not necessarily
to achieve a vocal outcome (as speech is not always the
most functional form of communication for some individ-
uals), but to use a system to functionally and sponta-
neously communicate in everyday situations (Bondy &
Frost, 2009; Frost & Bondy, 2002).
Communication Competence
The ability to communicate is complex and encom-
passes far more than just verbalization (Light, 1989), and
a number of researchers have characterized the func-
tional communication needs of individuals who use AAC
Address all correspondence and reprint requests to Cheryl
Ostryn, Department of Educational and School Psychology,
Penn State University, 122 CEDAR Building, University Park,
PA 16802-3109. E-mail: cuo112@psu.edu
Research & Practice for Persons with Severe Disabilities
2008, Vol. 33, No. 1Y2, 13–24
copyright 2009 by
TASH
13
(Cafiero, 2005; Mirenda & Mathy-Laikko, 1989; Ogletree
& Oren, 2006). Cooley and Roach (1984) use the term
Bcommunication competence[to describe the goal of
communication as having the knowledge of what com-
munication patterns are and how they are used appro-
priately in specific situations. Light and Binger (1998)
further defined communication competence as the ability
of an individual to be functional enough to communicate
in daily life within natural settings; to have satisfactory
knowledge, judgment, and skill in communicating; and
to reach communication goals. As noted by researchers,
communication competence goes beyond expressing
wants and needsVit encompasses both knowledge and
ability (Light & Binger, 1998). According to Light and
Binger, attaining communication competence for indi-
viduals who use AAC systems depends on the assimila-
tion of their knowledge, judgment, and skills across four
domain areas: linguistic, operational, social, and strategic.
In addition, Light’s (2003) paradigm identifies four main
types of interactions intended to fulfill communication
goals for individuals using AAC systems: expressing
needs and wants, developing social closeness, exchanging
information, and fulfilling social etiquette requirements
(see Table 1; Light, 1988, 1989, 2003). Recently, several re-
searchers have highlighted the usefulness of this func-
tional communication paradigm due to its application in
daily life (Blockberger & Sutton, 2003; Cafiero, 2005; Hoag,
Bedrosian, Johnson, & Molineux, 1994; Raghavendra,
Bornman, Granlund, & BjPrck-#kesson, 2007). Light’s
paradigm of communication competence is particularly
salient for nonvocal individuals because it is built upon
previous research and offers one of the most detailed com-
munication competence paradigms recognized in the cur-
rent literature (Blockberger & Sutton, 2003; Cafiero, 2005;
Hoag et al., 1994; Raghavendra et al., 2007).
As with most behaviors, knowledge of communication
can be manifested in the development of abilities. That
is, an individual needs a knowledge base of how to com-
municate before being able to perform a behavior (e.g.,
knowing that one should reply to a greeting in a friendly
manner with Bhello[or Bhow are you?[). Although knowl-
edge is an important construct, researchers and educa-
tors rely primarily on evidence of skills to evaluate present
levels of functioning and thus gauge improvement over
time. To address communication skill levels, desired out-
comes must be operationally defined. It is through clear
operationalization of abilities that progress can be moni-
tored and goal attainment be noted. For the purpose of
this review, communication competence components have
been operationalized based on skills identified in com-
munication research related to individuals with ASDs.
Common skills identified in communication research
include: (a) generalized ability (Schlosser & Lee, 2000;
Stokes & Baer, 1977), (b) spontaneous ability (Reichle &
Sigafoos, 1991), (c) joint attention ability (Bruinsma,
Koegel, & Koegel, 2004; Hoff, 2005; Jones & Carr, 2004;
Mundy & Crowson, 1997), and (d) maintenance (Schlosser
& Lee, 2000). Table 1 shows the conceptualization of
the operationalized communication competence para-
digm used in this review of the PECS research related to
individuals with ASDs.
The first operationalized communication competence
ability examined is generalization. Generalized commu-
nication ability involves individuals demonstrating the
competence to use knowledge to communicate in every-
day settings other than those associated with training
(e.g., environments or individuals different than those
involved in initial instruction). Generalization of abili-
ties involves achieving communication goals with a wide
range of individuals and stimuli, having the ability to
satisfy communication needs by gaining information
from others, and communicating appropriately depend-
ing on the social and cultural norms of a given situation
(Schlosser & Lee, 2000; Stokes & Baer, 1977).
The second communication competence ability ex-
amined is spontaneous communication ability. This abil-
ity involves individuals achieving their communication
goals without prompting by instructional cues (but us-
ing cues that are a part of the natural environment sur-
rounding that communication; Reichle & Sigafoos, 1991).
The third communication competence ability, joint atten-
tion, also involves the demonstration of achieving com-
munication goals but with the added emphasis on others;
joint attention can be defined as BIattending simulta-
neously with another individual to an event or object, with
each partner understanding that the other is sharing the
same focus[(Neisworth & Wolfe, 2005, p. 115). Among
other skills, joint attention can encompass the ability to
share and convey information and to develop social close-
ness. It has widely been reported that many individuals
with ASDs display impairments in sharing and conveying
information as evident in deficits of eye gaze, pointing
or indicating, and the social aspect of persistence to gain
attention from a communicative partner (Bruinsma
et al., 2004; Hoff, 2005; Jones & Carr, 2004; Mundy &
Crowson, 1997). The final communication competence
ability is the maintenance or the ongoing use of skills over
time. Maintenance is important to examine when evalu-
ating a communication intervention as communication
skills must be retained and built on over time (Schlosser
& Lee, 2000).
In this review, research involving the use of the PECS
with individuals having ASDs was examined, first by
identifying the dependent variables and outcomes re-
ported in the research, and second, by applying the com-
munication competence paradigm to the PECS research
as a means to assess whether individuals with ASDs have
the competence or skills necessary to functionally com-
municate in any setting and/or for any reason.
Method
An ERIC, PsychINFO, and PubMed database search
was conducted for peer-reviewed articles from 1985 (year
14 Ostryn et al.
Table 1
Four Domains of the Communication Competence Model Arranged Into Outcome Measures of Generalized Ability, Spontaneous Ability, Joint Attention Ability, and Maintenance
Interaction type Communication goal Generalized ability Spontaneous ability Joint attention ability Maintenance
Express needs
and wants
To regulate the behaviors
of others to fulfill needs
and wants (Light, 1988)
Get partner’s attention
as required
Get partner’s attention as required Get partner’s attention as required
Indicate desired (or rejected)
object or action
Indicate desired (or rejected)
object or action
Indicate desired (or rejected)
object or action
Terminate interaction Use politeness markers
as appropriate
Develop social
closeness
To establish and develop
personal relationships
(Light, 1988)
Identify shared activities/
objects that are of
mutual interest
Initiate interaction through
shared activities/topics
Identify shared activities/objects
that are of mutual interest
Continue to participate
actively through the
interaction
Identify appropriate opportunities
to participate
Initiate interaction through
shared activities/topics
Continue to participate actively
through the interaction
Make eye contact and attend to
the partner’s comments,
questions, and actions
Provide appropriate listener feedback
to the partner (e.g., smile, nod)
Fulfill turn opportunities with
appropriate questions, comments,
or actions
Express positive affect/empathy
as appropriate
Resolves conflicts appropriately
Continue to participate actively
through the interaction
Exchange
information
To obtain information and/
or impart information to
others (Light, 1988)
Identify appropriate opportunities
to ask questions or share
information on a topic
Identify appropriate
opportunities to ask
questions or share
information on a topic
Attend to partner’s comments
and questions
Continue to fulfill these
demands throughout
the extent of the
interaction
Produce a contingent response
to the partner’s question or
produce an appropriate
comment/question using
available vocabulary
Produce a contingent
response to the partner’s
question or produce an
appropriate comment/
question using available
vocabulary
Identify appropriate opportunities
to ask questions or share
information on a topic
Add additional relevant
information to develop
the topic
Initiate new topics
as appropriate
Confirm partner’s understanding
or clarity as required
Fulfill social
etiquette
requirements
To conform to social
conventions of politeness
(Light, 1988)
Identify required opportunities
to participate and fulfill
as required
Identify required opportunities
to participate and fulfill
as required
Identify required opportunities
to participate and fulfill
as required
15Picture Exchange Communication System, Autism
the PECS was developed) to 2007 in English, using the
following keywords: the PECS, picture exchange, AAC,
augment*, Autis*, communicat*, and perv*. Articles were
then evaluated using the following inclusion criteria:
1. used an experimental or quasi-experimental
design;
2. included individuals under 18 years old with ASDs;
3. involved the PECS as an intervention; and
4. published in peer-reviewed journal.
Fourteen articles from the database search and one
from the PECS Web site met the inclusion criteria. An
ancestral search was conducted on the 15 articles but
yielded no further articles. Although there is a great
deal of literature published on the PECS, many of these
articles did not meet the inclusion criteria, such as studies
that investigated variations of the PECS (Frea et al., 2001),
those that did not use participants with ASDs (Bock,
Stoner, Beck, Hanley, & Prochnow, 2005), and those that
did not investigate the PECS as the independent variable
(Howlin, Gordon, Pasco, Wade, & Charman, 2007).
Results and Discussion
The overarching goal of the PECS is similar to the
goal identified in the communication competence para-
digm. That is, both the PECS and the communication
competence paradigm seek to enable an individual to
functionally and spontaneously communicate in natural
settings (Bondy & Frost, 2009; Frost & Bondy, 2002;
Light, 1988, 1989, 2003). Although the general goals of
the PECS and communication competence paradigm are
similar, results from this review suggest that in its present
form the PECS may need to be supplemented with other
communication systems to permit individuals with ASDs
to gain full communication competence.
Research Designs and Overall Outcomes
The research designs are presented in Table 2; most
studies were either a variation of a multiple baseline
design or another single-subject design. Interestingly,
there were only three articles that employed a compari-
son of the PECS with another intervention (see Table 3).
Of the three comparison articles, only one study reported
positive outcomes (Adkins & Axelrod, 2001), another
reported mixed results (Tincani, 2004), and the third
article reported nonsignificant results (Yoder & Stone,
2006). Interestingly, these results were obtained in the
only study using an experimental design. Another study
demonstrated that only 5 of 24 participants in the experi-
mental group demonstrated increases in spoken words, or
less than a 25% success rate for the PECS intervention
Table 2
Study Sample Size and Outcomes of Generalized Ability, Spontaneous Ability, Joint Attention Ability, and Maintenance
Study Sample size Phases
a
Gen
b
Spont
c
Join Att
d
Maint
e
Adkins and Axelrod (2001)
f,g
11XXYY
Carr and Felce (2007)
h,i
41 3 X X YY
Charlop-Christy, Carpenter, Le, LeBlanc, and Kellet (2002)
g,j
36XXXX
Ganz and Simpson (2004)
g,k
34XXYY
Kravits, Kamps, Kemmerer, and Potucek (2002)
g,l
13XXXY
Liddle (2001)
g,i
20 6 YY Y Y
Magiati and Howlin (2003)
g,i
34 6 YY Y Y
Marckel, Neef, and Ferreri (2006)
g,m
25XYYY
Schwartz, Garfinkle, and Bauer (1998; Study 1)
g,i
31 4 X YYY
Schwartz et al. (1998; Study 2)
g,i
18 4 X X X X
Tincani (2004)
f,h
23XXYY
Tincani, Crozier, and Alazetta (2006; Study 1)
g,j
24XXYY
Tincani et al. (2006; Study 2)
h,j
14XYYY
Yoder and Stone (2006)
n,o
36 6 X YYY
Yokoyama, Naoi, and Yamamoto (2006)
g,j
35XYYX
Note. Dashes indicate the outcome was not reported.
a
Phases: phases investigated in study.
b
Gen: generalized outcomes occurred.
c
Spont: spontaneous outcomes occurred.
d
Join Att: joint attention outcomes occurred.
e
Maint: maintenance outcomes occurred.
f
Alternating treatments design.
g
Positive outcomes (for further details, refer to Table 2).
h
Mixed results.
i
Quasi-experimental.
j
Multiple baseline across participants.
k
Single subject within subjects.
l
Multiple baseline across settings.
m
Multiple baseline across descriptors.
n
Nonsignificant results.
o
Experimental comparison between interventions.
16 Ostryn et al.
Table 3
Study Variables, Including the Number of Phases Taught, Settings, Dependent Variables, and Reported Outcomes
Study Phases Setting Dependent variable(s) Reported outcomes
Adkins and
Axelrod (2001)
a,b
1 Participant’s typical autism
support classroom
Spontaneous and generalization
of manding
The PECS produced more generalizations and spontaneous
responses
Carr and Felce
(2007)
a
3 Participants’ school
environment
The correlation between the
PECS and the development
of spoken language
Control group, 1 of 17 demonstrated minimal increase
and 4 demonstrated a decrease in spoken words;
5 of 24 in the experimental group demonstrated
increase in spoken words.
Charlop-Christy
et al. (2002)
a
6 University clinic setting, empty
university classrooms, participants’
classrooms and homes
The PECS acquisition, speech emergence
in play and academic settings
Learning criterion met, showed concomitant increases in
verbal speech, ancillary gains associated with social-
communicative behaviors and problem-behavior decreasing
Ganz and Simpson
(2004)
a
4 Participants’ elementary
school classrooms
Number of spoken words, complexity
and length of phrases, decreasing
nonword vocalizations
Word utterances increased in number of words
and grammar complexity
Kravits et al.
(2002)
a
3 Leisure and snack time in
participants’ homes and
play periods with peers
during journal and center
activities at school
Spontaneous communications across
home and school, social interaction
Increase in spontaneous requests and comments,
verbalizations in two of three settings, changes in
social interaction in one of two school settings
Liddle (2001)
a
6 Participants’ classrooms Length of phase acquisition,
increases in vocalizations/word use
20 acquired the PECS (Phase 2: 1Y11 months; Phase 3:
1Y11 months; Phase 5: 8Y11 months; and Phase 6:
4Y15 months); increases in word vocalizations/word
use, 7 of the 20 speaking with single words, 1 using
sentences, 1 attempting but unintelligible
Magiati and Howlin
(2003)
a
6 Eight special schools for
children with autism in
South England
Child: Number, frequency of the PECS
communications, increases in other forms of
communication, occurring behavioral changes
Significant, rapid increases in the PECS levels, vocabulary,
and frequency; slow occurring general level of
communication
Marckel et al.
(2006)
a
5 Participants’ homes Manding by improvising using descriptors
when specific pictures were unavailable
Training increased number of improvised requests,
skills generalized across items, settings, and
listeners in natural environments
Schwartz et al.
(1998; Study 1)
a
4 Children’s classrooms Rate of the PECS acquisition, manding only Acquisition average 14 months
17Picture Exchange Communication System, Autism
Study Phases Setting Dependent variable(s) Reported outcomes
Schwartz et al.
(1998; Study 2)
a
4 Children’s classrooms The PECS use during snack time
and free-choice activities
The PECS generalizes to untrained settings, may have
concomitant effects on untrained language functions
Tincani (2004)
a,b
3 Self-contained classroom for
children with multiple
disabilities within a
public school
Manding and vocal behavior acquisition Participant 1Vsign language produced higher percentage
of mands, Participant 2VThe PECS produced higher
percentage of mands; both sign produced higher percentage
of vocalizations during training; acquisition of systems
may vary as a function of individual student characteristics
Tincani et al.
(2006; Study 1)
a
4 Self-contained classroom or in
a separate room with a table
and chairs, depending on the
availability of space
Manding and speech development Increases in manding, only one participant produced
measurable speech during Phase 4
Tincani et al.
(2006; Study 2)
a
4 Self-contained classroom or in
a separate room with a table
and chairs, depending on the
availability of space
Determine a functional relationship
between Phase 4 and speech development
using a vocal reinforcement procedure
No measurable words emitted, so used vocal approximations;
differentially higher percentage produced while
reinforcement delay procedure in effect, but results
suggest the reinforcement delay procedure had little
influence on level of independent mands
Yokoyama et al.
(2006)
a
5 A university room for one
participant, and the homes
for the other participants
Acquisition of elementary communication skills
using the PECS, incorporating task analysis
Acquisition of basic components of the PECS within a
short period; data from task analysis showed increased
use of the PECS and prior mode of communication
(grabbing, reaching, crying) was replaced
Yoder and Stone
(2006)
a,c
6 University clinic Facilitating generalized object exchange turn
taking, facilitating requests, facilitating
initiating joint attention
RPMT facilitated frequency of generalized turn taking and
generalized initiating joint attention more than the PECS.
The latter effect occurred only for children who began
treatment with at least some initiating joint attention; in
contrast, the PECS facilitated generalized requests more
than the RPMT in children with very little initiating
joint attention prior to treatment; joint attention grew in
both conditions, but RPMT was superior to the PECS
in facilitating initiating joint attention
a
Independent variable: PECS.
b
Independent variable: Sign Language.
c
Independent variable: Responsive Education and Prelinguistic Milieu Teaching.
Table 3
(continued)
18 Ostryn et al.
(Carr & Felce, 2007). Given the paucity of empirical
studies, these results highlight the need for more experi-
mental studies (both involving control groups and single-
subject research methodology) to investigate whether the
PECS is an effective system of communication in relation
to other communication systems.
Dependent Variables
Despite its widespread use with children with ASDs
(Anderson et al., 2007; Simpson et al., 2005), only 15 em-
pirical studies were located with the outlined search cri-
teria. As reported in Table 2, all but four studies reported
positive overall outcomes (Carr & Felce, 2007; Tincani,
2004; Study 2 in Tincani et al., 2006; Yoder & Stone, 2006).
The term positive outcomes is used to describe positive
results in relation to the dependent variables investigated,
with no relation to statistical significance. Dependent var-
iables examined in the PECS research included acquisi-
tion rate and speech emergence.
Acquisition rate
Liddle (2001) reported the PECS acquisition of Phase
2 averaged between 1 and 11 months, Phase 3 averaged
between 1 and 11 months, Phase 5 averaged between
8 and 11 months, and Phase 6 averaged between 4 and
15 months. Schwartz et al. (1998) reported an average of
14 months acquisition time to Phase 4, with a range of
3Y28 months (Study 1). The remaining two studies did
not report specific time frames (Charlop-Christy et al.,
2002; Magiati & Howlin, 2003). It may be important to
examine acquisition rates because instructional time
must be used wisely when working with individuals with
ASDs; many individuals have significant communication
and cognitive deficits, making the acquisition of skills
more time consuming. Although several researchers in-
dicated that acquisition rates for the PECS phases were
fast (Charlop-Christy et al., 2002; Liddle, 2001; Magiati
& Howlin, 2003; Study 1 in Schwartz et al., 1998), the
available results did not clearly define how Bfast[was
operationalized. Further, in the present review, acquisi-
tion rates for all six phases of the PECS were not ex-
amined. It is probable that acquisition rates for the
phases would vary and reported rates would be of use to
future PECS researchers.
Speech emergence
Vocal outcomes associated with expressive communica-
tion included frequency of utterances (Charlop-Christy
et al., 2002; Ganz & Simpson, 2004; Liddle, 2001; Study 1
in Tincani et al., 2006), grammar complexity (Ganz &
Simpson, 2004), percent of vocalizations (Tincani, 2004),
percentage of vocal approximations (Study 2 in Tincani
et al., 2006), and development of spoken language (Carr
& Felce, 2007). The investigation of verbal outcomes is
interesting, given that speech is not a required outcome
of the PECS because it may not always be the most
functional form of communication for some individuals
(Mesibov, Adams, & Klinger, 1997). Some of the results
from the studies are promising in the area of speech de-
velopment, but because the PECS was designed to offer a
system for nonvocal individuals to communicate (Bondy
& Frost, 2002), it is important to acknowledge that the
PECS system may not be credited for speech emergence.
That is, because the PECS is not intended to lead to
speech production, language development can be viewed
as an ancillary outcome of the PECS interventions.
Given the explicit goal of the PECS, perhaps a more use-
ful outcome would be to focus on the quality of the com-
municative exchanges, as opposed to the form. Quality
of communication competence variables could include
variables such as joint attention components or correct
word order.
Operationalized Communication
Competence Components
When operationalized components of the communica-
tion competence paradigm were applied to reported out-
comes of the PECS research, results suggest that many of
the components of communication competence for indi-
viduals with ASDs do not appear to be systematically
addressed. Results of the operationalized communica-
tion competence abilities of generalization, spontaneous
communication, joint attention, and maintenance are pre-
sented in Table 2.
Generalization
One skill frequently examined by researchers was
generalization of communication skills; demonstration
of the ability to exchange pictorial representations for
items was examined throughout all six phases of the
PECS. Specifically, individuals with ASDs who commu-
nicated using the PECS were able to continue gener-
alizing their learned communications throughout the
phases investigated in the particular study (e.g., Adkins
& Axelrod, 2001; Carr & Felce, 2007; Charlop-Christy
et al., 2002; Ganz & Simpson, 2004; Kravits et al., 2002;
Marckel et al., 2006; Study 1 and Study 2 in Schwartz
et al., 1998; Tincani, 2004; Study 1 and Study 2 in Tincani
et al., 2006; Yoder & Stone, 2006; Yokoyama et al., 2006).
These findings represent very positive results. However,
when applying the communication competence para-
digm, generalization of the PECS outcomes may be
enhanced in a number of ways. Generalization of com-
munication skills could be enhanced by identification of
shared activities/objects of mutual interest and identifica-
tion of appropriate opportunities to ask questions or share
information on a topic (a) to produce a contingent re-
sponse to the partner’s question, (b) to produce an appro-
priate comment/question using available vocabulary, and
(c) to add additional relevant information to develop a
topic. Further, these skills would be useful to enable indi-
viduals with ASDs to participate in more complex com-
munication exchanges rather than primarily manding or
commenting.
19
Picture Exchange Communication System, Autism
Spontaneous communication
Although initiating spontaneous communications is a
key element of the PECS, it was less systematically
examined in the current review (Adkins & Axelrod, 2001;
Carr & Felce, 2007; Charlop-Christy et al., 2002; Ganz
& Simpson, 2004; Kravits et al., 2002; Study 2 in Schwartz
et al., 1998; Tincani, 2004; Study 1 in Tincani et al., 2006).
Further, the existing research did not explicitly define
spontaneous exchanges, particularly in relation to the
desired item making comparison of this outcome difficult.
For example, although the PECS procedure states that
highly desired items be in view, only two studies explic-
itly defined spontaneous outcomes in relation to visual
prompts (Charlop-Christy et al., 2002; Yoder & Stone,
2006). Specifically, individuals with ASDs may have been
visually prompted by their open communication books
versus finding the item without such a prompt. Although
two other studies explicitly defined spontaneous commu-
nication, the authors did not reference if, or how, visual
prompts were used (Ganz & Simpson, 2004; Study 1 in
Tincani et al., 2006). Future research would be enhanced
with procedures explicitly noted and procedural fidelity
measures included.
When discussing spontaneous communication out-
comes for individuals having ASDs, it is important to
note that young typically developing children do not
communicate spontaneously for items out of sight when
they are first learning to communicate (Rollins, Wambacq,
Dowell, Mathews, & Britton Reese, 1998). However,
young typically developing children do engage in commu-
nications by asking Bwh[questions about their environ-
ment such as Bwhat,[Bwhere,[Bwho,[Bwhy[(and Bhow[;
Deevy & Leonard, 2004; Light & Binger, 1998; Taylor &
Harris, 1995). Thus, when targeting spontaneous commu-
nication outcomes using the PECS, it would be beneficial
to target spontaneous attempts for not only obtaining ob-
jects but also for question asking. Arguably, it may be in-
accurate to compare conversations of typically developing
children to those with ASDs because these children gener-
ally are less motivated to engage in social interactions and
often prefer tangible reinforcement. However, using the
communication competence paradigm, it may be useful to
explicitly program question asking into the PECS. This
instruction could occur by asking individuals about con-
crete items in their environment. For example, instructors/
researchers could permit the child with ASD to see a small
part of a new flashing toy and require them to ask Bwhat’s
that?[by pointing to a picture (Taylor & Harris, 1995;
Williams, Donley, & Keller, 2000) or hiding a favorite item
and require them to ask BWhere is it?[or BWhere’s my
car?[Although the PECS does teach commenting, ques-
tion asking may further empower individuals with ASDs
and thus give them greater control over their environment.
Joint attention
Not surprisingly, joint attention is a critical component
of the communication competence paradigm because,
at its foundation, communication is a social act. Because
joint attention is a core deficit for individuals with
ASDs, it seems prudent to examine it more explicitly in
the PECS research literature. As other researchers have
noted, joint attention outcomes can be difficult to mea-
sure, as it is difficult to address the true social nature of
joint attention (Jones & Carr, 2004) and to engage
children with autism in joint attention activities (Rollins
et al., 1998). In related research, joint attention has been
operationalized as eye gaze, pointing, showing, and social
referencing among others (Ben-Arieh, 2007; Bruinsma
et al., 2004; Jones & Carr, 2004). These same dependent
variables could be used to measure joint attention in
the PECS.
The importance of joint attention in spontaneous com-
munication competence has been noted by several re-
searchers. For example, Toth, Munson, Meltzoff, and
Dawson (2006) found that joint attention was signifi-
cantly associated with the rate of communication skills
over time. Similarly, Whalen, Schreibman, and Ingersoll’s
(2006) study supported the theory that joint attention
may be developmentally linked with language; these
authors found participants with autism who received joint
attention training made substantial gains in spontaneous
speech resembling typically developing children. Given
its pivotal role in communication competence, it is recom-
mended that joint attention, however it is measured, be
explicitly programmed in all AAC systems, including the
PECS. These findings also point to the need to program
for joint attention skills throughout all phases of the
PECS interventions.
As noted in Table 3, variables associated with joint
attention were reported in 3 of the 15 studies; all three
studies addressed joint attention as requesting and turn
taking (Charlop-Christy et al., 2002; Kravits et al., 2002;
Study 2 in Schwartz et al., 1998). Of interest, however,
is that none of the studies examined an aspect of joint
attention that has been widely noted as a deficit of stu-
dents with ASDs, that is, eye gaze (Mundy & Crowson,
1997). It is questionable as to why joint attention
skills were not investigated in most of the reviewed
studies. Perhaps as identified in Light’s (2003) commu-
nication competence paradigm, joint attention measures
may require vocabulary that encompasses more than
requesting and commenting. For example, individuals
having ASDs may require a richer vocabulary than
often is encountered in the PECS system to initiate
interactions through shared activities/topics and to par-
ticipate in turn-taking opportunities through the use of
appropriate questions, comments, or actions. Viewing
joint attention through the communication competence
paradigm, it could be argued that it would be more
beneficial to teach question asking in Phase 6 of the
PECS rather than commenting, which is the central
outcome in the final phase, because more control may
be gained by the individual with ASD over his or her
environment.
20 Ostryn et al.
Maintenance
The present review also revealed few studies exam-
ining the maintenance of the PECS outcomes (Charlop-
Christy et al., 2002; Study 2 in Schwartz et al., 1998;
Yokoyama et al., 2006). Specifically, Schwartz et al.
(1998) designed their study as a 1-year follow-up and,
among the 18 participants, generalized, spontaneous,
and vocal outcomes were maintained (Study 2). Charlop-
Christy et al. (2002) reported that one out of three
participants maintained 100% spontaneous speech and
an increased length of utterances during the 1-year
follow-up. Yokoyama et al. (2006) reported that at 6- and
8-month follow-ups, maintenance was high with the three
participants’ response levels as above 87.5%, 100%, and
above 75% on maintenance testing. Results of mainte-
nance outcomes are encouraging. It would be of use to re-
searchers to continue to measure maintenance effects. A
related benefit of examining maintenance may be the con-
tinued identification of the adequacy/comprehensiveness
of an individual’s repertoire of icons/pictures for evolving
communication needs.
General Discussion
There is little debate that the PECS is widely used for
individuals having ASDs; however, given the paucity of
empirical studies related to outcomes, it is important
that more research should occur. Drawing from research
related to individuals having ASDs, this review applied
the communication competence paradigm to the PECS
outcomes. Although the authors of this present review
operationalized outcomes detailed in the communication
competence paradigm (i.e., generalization, spontaneous
communication, joint attention, and maintenance), the
communication competence components themselves
remained unchanged. The application of the communi-
cation competence paradigm should not be viewed as an
effort to hold the PECS to a Bhigher[standard than other
AAC systems but rather to suggest that the communica-
tion competence paradigm be considered as the ultimate
outcome of all communication systems in effect, a Bgold
standard.[Using communication competence as the
overarching goal of any communication system will per-
mit individuals with ASDs to participate in any setting
(inclusive schools and community settings) at anytime.
The current review appears to echo research undertaken
in the communication field; that is, the most effective
communication system may be no one single system but
rather a Bmultimodal approach[(Cress & Ball, 1998;
Drager, Light, & Finke, 2009; Light, Roberts, DiMarco,
& Greiner, 1998; Mar & Sall, 1999). The multimodal
approach to communication competence could use com-
ponents of the PECS such as manding or tacting. How-
ever, as identified in this review, to attain communication
competence additional strategies should be addressed
including teaching individuals with ASDs conversational
vocabulary unrelated to requesting, teaching Bwh[ques-
tions, adapting phrases to suit the learner, enhancing
motivation to encourage joint attention skills, and moni-
toring progress over time. As outlined in the literature,
many factors must be examined when selecting a com-
munication system such as motor abilities, cognitive abil-
ities, and age appropriate communication needs (Parette,
Hourcade, & VanBiervliet, 1993). Until an evaluation is
undertaken of the individual’s communication abilities,
it is possible that teaching an individual to use pictures
may be a disservice. Research related to multimodal
approach for communication competence highlights the
need to encourage and to respond to all communication
attempts, be it speech, vocal approximations, or gestures.
Use of all communication attempts may have implica-
tions for systems like the PECS; specifically, rather em-
ploying multimodal systems does not force individuals
to choose a sole communication system to use but allow
them to use several components together. For example,
the PECS system can be used in combination with an
electronic device programmed to ask questions to ex-
change information and to express emotions.
When employing a multimodal system, one must rec-
ognize the efficiency and the social validity of the com-
munication system. For instance, using gestures or signs
when trying to gain attention from another at a distance
may be more efficient, but pictures may be more effi-
cient when communicating with someone close by. There
are many elements to consider in choosing an AAC
system, and all decisions must be individualized to meet
the communications needs of each individual (Iacono
& Caithness, 2009). Currently, there is no formal eval-
uation procedure to determine for whom the PECS may
be well suited. The only evaluative component outlined
indicates that the PECS is likely for candidates if they (a)
cannot functionally communicate, (b) are frequently mis-
understood, (c) do not use language complex enough to
meet their needs, and (d) do not spontaneously commu-
nicate (Frost & Bondy, 2002). However, these evaluation
criteria are insufficient to determine whether the PECS
is more effective than other competing AAC systems.
Future Research or Suggestions
Drawing on results of the current review and existing
research related to ASD and communication (Bruinsma
et al., 2004; Hoff, 2005; Jones & Carr, 2004; Mundy &
Crowson, 1997; Reichle & Sigafoos, 1991; Schlosser
& Lee, 2000), the following suggestions may serve to
guide future research and implementation of the PECS
to achieve communication competence for individuals
with ASDs.
1. Generalization. Introduce and teach vocabulary re-
lated to conversational communicative exchanges
and the Bwh[questions to enable individuals to par-
take in communications suchas BWhat is that noise?[
and BWhere are we going?[Identify activities/
objects of mutual interest to the individuals with
ASDs and typically developing peers.
21
Picture Exchange Communication System, Autism
2. Spontaneous communication. Operationally define
spontaneous communication; record communica-
tions with and without objects in sight. Use surveys
to ensure that items include those found in natural
environments. Systematically reevaluate vocabu-
lary and icons as communication needs change over
time. If examining vocal outcomes related to the
PECS, measure both the quality and the content
of utterances in conjunction with frequency and
length. Examine acquisition rates for individuals
with ASDs across all the PECS phases to help
determine whether particular individuals can or
should progress through all six phases or whether
other communication systems should be used in
conjunction with the PECS.
3. Joint attention. Use measures of joint attention used
in other communication research, including eye gaze,
pointing, showing, and social referencing among
others, within the PECS.
4. Maintenance. Use a maintenance schedule to re-
cord mastered skills over time, for example, every
3 months, to ensure all skills are maintained. Con-
tinue to reevaluate vocabulary needs as they change
over time.
Results of this study reveal that the PECS is widely
implemented with individuals having ASDs but without
a strong empirical base. Experimental studies that ex-
amine the effectiveness of the PECS as compared to
other communication systems can be critically needed.
Using Light’s communication competence paradigm
serves to remind professionals that all communication
should be valued if it leads to functional communication
and meets the needs of the individual. As identified in
the literature, communication needs are highly individ-
ualized and subject to change over time (Mirenda, 2009).
Given such individualization, it may be most useful to
consider the PECS as one component of a multimodal
approach (Cress & Ball, 1998; Drager et al., 2009; Light
et al., 1998; Mar & Sall, 1999). Other communication
systems may be needed to permit communication beyond
manding and tacting. As Light’s paradigm notes, it is
important to be able to ask questions, to develop social
closeness, and to exchange information. Future research-
ers should also examine whether individuals are best
matched with the PECS. The PECS may inadvertently
limit alternate modes of communication. Ultimately,
research related to any communication system should
evaluate whether communication competence has been
achieved. Without these outcomes, communicative op-
portunities for individuals with ASDs may be restricted
and abilities unrealized.
This study has highlighted some important aspects of
the PECS in relation to having a functional method to
communicate, but there are many unanswered questions
still to address. For whom should the PECS be recom-
mended? The present results suggest that the PECS is
probably best used as an initial intervention to teach
manding and the basic elements of what is a communi-
cative exchange. However, it is not recommended for
a long-term intervention as it does not address ques-
tion asking and may be better implemented as part of
a multimodal system for when picture communications
are more socially appropriate. Individuals should be
transitioned from pictures because it is probably not
socially valid to have older adolescents and adults using
pictures to communicate; in this respect, using a voice-
output box may be more appropriate. Also, as vocab-
ulary grows, so does the need to carry around more
pictures, and this issue needs careful consideration. Fur-
thermore, does using the PECS create a disadvantage
for other AAC systems?Va question that research can
systematically address. In conclusion, communication
system choices are highly individualized and should
be based on solid research (Mirenda, 2009). It is im-
perative that communication competence is the ultimate
outcome of a communication system for individuals
with ASDs.
References
Adkins, T., & Axelrod, S. (2001). Topography-versus selection-
based responding: Comparison of mand acquisition in each
modality. Behavior Analyst Today,2, 259Y266.
Anderson, A., Moore, D., & Bourne, T. (2007). Functional
communication and other concomitant behavior change fol-
lowing PECS training: A case study. Behavior Change,24,1Y8.
Ben-Arieh, J. (2007). How to use joint attention routines. Austin
Texas: Pro-Ed Series on Autism Spectrum Disorders.
Blockberger, S., & Sutton, A. (2003). Toward linguistic com-
petence: Language experiences and knowledge of children
withextremelylimitedspeech.InJ.C.Light,D.R.Beukelman,
& J. Reichle (Eds.), Communicative competence for individuals
who use AAC. Baltimore: Paul H. Brookes.
Bock, S. J., Stoner, J. B., Beck, A. R., Hanley, L., & Prochnow, J.
(2005). Increasing functional communication in nonspeak-
ing preschool children: Comparison of PECS and VOCA.
Education and Training in Developmental Disabilities,40,
264Y278.
Bogdashina, O. (2005). Communication issues in autism and
Asperger syndrome. London: Jessica Kingsley Publishers.
Bondy, A., & Frost, L. (1994). The Picture Exchange Commu-
nication System. Focus on Autistic Behavior,9,1Y19.
Bondy, A., & Frost, L. (2001). The Picture Exchange Commu-
nication System. Behavior Modification,25, 725Y744.
Bondy, A., & Frost, L. (2002). A picture’s worth: PECS and
other visual communication strategies in autism. Bethesda,
MD: Woodbine House.
Bondy, A., & Frost, L. (2009). The Picture Exchange Commu-
nication System. Clinical and research applications. In P.
Mirenda & T. Iacono (Eds.), Autism spectrum disorders AAC.
Baltimore: Paul H. Brookes.
Bruinsma, Y., Koegel, R. L., & Koegel, L. K. (2004). Joint
attention and children with autism: A review of the litera-
ture. Mental Retardation and Developmental Disabilities,10,
169Y175.
Cafiero, J. M. (2005). Meaningful exchanges for people with
autism. Bethesda, MD: Woodbine House.
Carr, D., & Felce, J. (2007). Brief report: Increase in production
of spoken words in some children with autism after PECS
teaching to phase III. Journal of Autism and Developmental
Disorders,37, 780Y787.
22 Ostryn et al.
Charlop-Christy, M. H., Carpenter, M., Le, L., LeBlanc, L. A.,
& Kellet, K. (2002). Using the Picture Exchange Communi-
cation System (PECS) with children with autism: Assessment
of PECS acquisition, speech, social-communicative behavior,
and problem behavior. Journal of Applied Behavior Analysis,
35, 213Y231.
Cooley, R. E., & Roach, D. A. (1984). A conceptual framework.
In R. Bostrom (Ed.), Competence in communication: A mul-
tidisciplinary approach. Beverly Hills: Sage Publications.
Cress, C., & Ball, L. (1998). Strategies for promoting vocal
development in young children relying on AAC: Three case
illustrations. Proceedings of the 21st Annual RESNA Con-
ference, Minneapolis, MN.
Deevy, P., & Leonard, L. B. (2004). The comprehension of
wh-questions in children with specific language impairment.
Journal of Speech, Language, and Hearing Research,47,
802Y815.
Drager, K. D. R., Light, J. C., & Finke, E.H. (2009). Using AAC
technologies to build social interaction with young children
with autism spectrum disorders. In P. Mirenda & T. Iacono
(Eds.), Autism spectrum disorders and AAC. Baltimore: Paul
H. Brookes.
Frea, W. D., Arnold, C. L., & Vittimberga, G. L. (2001). A
demonstration of the effects of augmentative communica-
tion on the extreme aggressive behavior of a child with autism
within an integrated preschool setting. Journal of Positive
Behavior Interventions,3,194Y198.
Frost, L., & Bondy, A. (2002). The Picture Exchange Communi-
cation System training manual. Newark, DE: Pyramid Edu-
cational Products.
Ganz, J. B., & Simpson, R. L. (2004). Effects on communicative
requesting and speech development of the Picture Exchange
Communication System in children with characteristics of
autism. Journal of Autism and Developmental Disorders,34,
395Y409.
Hoag, L. A., Bedrosian, J. L., Johnson, D. E., & Molineux, B.
(1994). Variables affecting perceptions of social aspects of
the communicative competence of an adult AAC user. Aug-
mentative and Alternative Communication,10, 129Y137.
Hoff, E. (2005). Language and development.Belmont,CA:
Wad swo rth .
Howlin, P., Gordon, R. K., Pasco, G., Wade, A., & Charman, T.
(2007). The effectiveness of Picture Exchange Communica-
tion System (PECS) training for teachers of children with
autism: A pragmatic, group randomized trial. Journal of
Child Psychology and Psychiatry,48, 473Y481.
Iacono, T., & Caithness, T. (2009). Assessment issues. In P.
Mirenda & T. Iacono (Eds.), Autism spectrum disorders and
AAC. Baltimore: Paul H. Brookes.
Jones, E. A., & Carr, E. G. (2004). Joint attention in children
with autism: Theory and intervention. Focus on Autism and
Other Developmental Disabilities,19,13Y26.
Kravits, T. R., Kamps, D. M., Kemmerer, K., & Potucek, J.
(2002). Brief report: Increasing communication skills for an
elementary-aged student with autism using the Picture Ex-
change Communication System. Journal of Autism and Devel-
opmental Disorders,32,225Y230.
Liddle, K. (2001). Implementing the Picture Exchange Commu-
nication System (PECS). International Journal of Language
and Communication Disorders,36, 391Y395.
Light, J., & Binger, C. (1998). Building communicative com-
petence with individuals who use augmentative and alternative
communication. Baltimore: Paul H. Brookes.
Light, J., Roberts, B., DiMarco, R., & Greiner, N. (1998). Aug-
mentative and alternative communication to support recep-
tive and expressive communication for people with autism.
Journal of Communication Disorders,31, 153Y180.
Light, J. C. (1988). Interactions involving individuals using
augmentative and alternative communication systems: State
of the art and future directions for research. Augmentative
and Alternative Communication,5, 137Y143.
Light, J. C. (1989). Toward a definition of communicative
competence for individuals using augmentative and alterna-
tive communication systems. Augmentative and Alternative
Communication,5, 137Y144.
Light, J. C. (2003). Shattering the silence: Development of com-
municative competence by individuals who use AAC. In J. C.
Light, D. R. Beukelman, & J. Reichle (Eds.), Communicative
competence for individuals who use AAC. Baltimore: Paul H.
Brookes.
Lord, C., Risi, S., & Pickles, A. (2004). Trajectory of language
development in autistic spectrum disorders. In M. L. Rice &
S. F. Warren (Eds.), Developmental language disorders: From
phenotypes to etiologies. Mahwah, NJ: Lawrence Erlbaum
Associates Publishers.
Magiati, I., & Howlin, P. (2003). A pilot evaluation study of the
Picture Exchange Communication System (PECS) for chil-
dren with autistic spectrum disorders. Autism,7,297Y320.
Mar, H., & Sall, N. (1999). Profiles of the expressive commu-
nication skills of children and adolescents with severe cogni-
tive disabilities. Education and Training in Mental Retardation
and Developmental Disabilities,34,77Y89.
Marckel, J. M., Neef, N. A., & Ferreri, S. J. (2006). A pre-
liminary analysis of teaching improvisation with the Picture
Exchange Communication System to children with autism.
Journal of Applied Behavior Analysis,39, 109Y115.
Mesibov, G. B., Adams, L. W., & Klinger, L. G. (1997). Autism:
Understanding the disorder. New York: Plenum.
Mirenda, P. (2009). Introduction to AAC for individuals with
autism spectrum disorders. In P. Mirenda & T. Iacono (Eds.),
Autism spectrum disorders and AAC. Baltimore: Paul H.
Brookes.
Mirenda, P., & Mathy-Laikko, P. (1989). Augmentative and al-
ternative communication applications for persons with se-
vere congenital communication disorders: An introduction.
Augmentative and Alternative Communication,5,3Y13.
Mundy, P., & Crowson, M. (1997). Joint attention and early
social communication: Implications for research on interven-
tion with autism. Journal of Autism and Developmental Dis-
orders,27, 653Y676.
Neisworth, J. T., & Wolfe, P. S. (2005). The autism encyclopedia.
Baltimore: Paul H. Brookes.
Ogletree, B. T., & Oren, T. (2006). How to use augmentative and
alternative communication. Austin Texas: Pro-Ed Series on
Autism Spectrum Disorders.
Parette, H. P., Jr., Hourcade, J. J., & VanBiervliet, A. (1993).
Selection of appropriate technology for children with dis-
abilities. Teaching Exceptional Children, 25,18Y22.
Raghavendra, P.,Bornman, J., Granlund, M., & BjPrck-)kesson,
E. (2007). The World Health Organization’s international
classification of functioning, disability, and health: Implica-
tions for clinical and research practice in the field of aug-
mentative and alternative communication. Augmentative and
Alternative Communication. Retrieved November 7, 2007,
from http://www.informaworld.com/smpp/title~content=
t713692248.
Reichle, J., & Sigafoos, J. (1991). Establishing spontaneity and
generalization. In J. Reichle, J. York, & J. Sigafoos (Eds.),
Implementing augmentative and alternative communication.
Baltimore: Paul H. Brookes.
Rollins, P. R., Wambacq, I., Dowell, D., Mathews, L., & Britton
Reese, P. (1998). An intervention technique for children with
autistic spectrum disorder: Joint attentional routines. Journal
of Communication Disorders,31, 181Y193.
Schlosser, R. W., & Lee, D. L. (2000). Promoting generalization and
maintenance in augmentative and alternative communication:
A meta-analysis of 20 years of effectiveness research.
Augmentative and Alternative Communication,16, 208Y226.
23Picture Exchange Communication System, Autism
Schwartz, I. S., Garfinkle, A. N., & Bauer, J. (1998). The Picture
Exchange Communication System: Communicative outcomes
for young children with disabilities. Topics in Early Childhood
Special Education,18,144Y159.
Simpson, R. L., de Boer-Ott, S. R., Griswold, D. E., Smith
Myles, B., Byrd, S. E., Ganz, J. B.,et al. (2005). Autismspectrum
disorders. Thousand Oaks, CA: Corwin Press.
Stokes, T. F., & Baer, D. M. (1977). An implicit technology of
generalization. Journal of Applied Behavior Analysis,10, 349Y367.
Taylor, B. A., & Harris, S. L. (1995). Teaching children with
autism to seek information: Acquisition of novel information
and generalization of responding. Jour na l of Ap pl ied B eh avi or
Analysis,28,3Y14.
Tincani, M. (2004). Comparing the Picture Exchange Commu-
nication System and sign language training for children with
autism. Focus on Autism and Other Developmental Disabilities,
19,152Y163.
Tincani, M., Crozier, S., & Alazetta, L. (2006). The Picture
Exchange Communication System: Effects on manding and
speech development for school-aged children with autism.
Education and Training in Developmental Disabilities,41,
177Y184.
Toth, K., Munson, J., Meltzoff, A. N., & Dawson, G. (2006).
Early predictors of communication development in young
children with autism spectrum disorder: Joint attention, imi-
tation, and toy play. Journal of Autism and Developmental
Disorders,66,993Y1005.
Whalen, C., Schreibman, L., & Ingersoll, B. (2006). The col-
lateral effects of joint attention training on social initiations,
positive affect, imitation, and spontaneous speech for young
children with autism. Journal of Autism and Developmental
Disorders,36,655Y664.
Williams, G., Donley, C. R., & Keller, J. W. (2000). Teaching
children with autism to ask questions about hidden objects.
Journal of Applied Behavior Analysis,33, 627Y630.
Worth, S. (2005). Autistic spectrum disorders. London: Continuum
Publishing Group.
Yoder, P., & Stone, W. L. (2006). Randomized comparison of
two communication interventions for preschoolers with au-
tism spectrum disorders. Journal of Consulting and Clinical
Psychology,74,426Y435.
Yokoyama, K., Naoi, N., & Yamamoto, J. (2006). Teaching
verbal behavior using the Picture Exchange Communication
System (PECS) with children with autistic spectrum dis-
orders. Japanese Journal of Special Education,43, 485Y503.
Received: August 12, 2008
Final Acceptance: December 27, 2008
Editor in Charge: Roberta Schnorr
24 Ostryn et al.
