ERIC EJ941686: A Comparison of Methods for Teaching Receptive Labeling to Children with Autism Spectrum Disorders

2011·2 MB·English

by  ERIC

JOURNALOFAPPLIEDBEHAVIORANALYSIS 2011, 44, 475–498 NUMBER3 (FALL2011)
A COMPARISON OF METHODS FOR TEACHING RECEPTIVE
LABELING TO CHILDREN WITH AUTISM SPECTRUM DISORDERS
LAURA L. GROW
MUNROE-MEYERINSTITUTE
UNIVERSITYOFNEBRASKAMEDICALCENTER
JAMES E. CARR
AUBURNUNIVERSITY
TIFFANY M. KODAK AND CANDICE M. JOSTAD
MUNROE-MEYERINSTITUTE
UNIVERSITYOFNEBRASKAMEDICALCENTER
AND
APRIL N. KISAMORE
WESTERNNEWENGLANDCOLLEGE
Many early intervention curricular manuals recommend teaching auditory-visual conditional
discriminations (i.e., receptive labeling) using the simple-conditional method in which
component simple discriminations are taught in isolation and in the presence of a distracter
stimulus before the learner is required to respond conditionally. Some have argued that this
proceduremightbesusceptibletofaultystimuluscontrolsuchasstimulusoverselectivity(Green,
2001).Consequently,therehasbeenacallfortheuseofalternativeteachingproceduressuchas
theconditional-onlymethod,whichinvolvesconditionaldiscriminationtrainingfromtheonset
of intervention. The purpose of the present study was to compare the simple-conditional and
conditional-only methods for teaching receptive labeling to 3 young children diagnosed with
autism spectrum disorders. The data indicated that the conditional-only method was a more
reliable and efficient teaching procedure. In addition, several error patterns emerged during
training using the simple-conditional method. The implications of the results with respect to
current teaching practices inearly intervention programsarediscussed.
Keywords: autism,conditionaldiscriminationtraining,earlyintervention,receptivelabeling,
stimuluscontrol
_______________________________________________________________________________
Conditional discriminations are one of the intensive behavioral intervention (EIBI) (e.g.,
most commonly targeted skills in early and matchingidenticalitems,receptivelanguage).A
conditional discrimination involves four com-
Thisarticleis basedonadissertation submittedbythe ponents: a sample stimulus, the presentation of
firstauthorunderthesupervisionofthesecondauthorin comparison stimuli, a response, and a conse-
partial fulfillment of the requirements for the doctoral
quence (Saunders & Spradlin, 1989, 1990). In
degree in behavior analysis from Western Michigan
University.WethankcommitteemembersWayneFuqua, atypicaltrialduringauditory-visualconditional
Linda LeBlanc, Cynthia Pietras, and Ivy Chong for their discrimination training, the teacher presents an
helpful comments. We also thank Scott McPhee,
array (usually two or three) of visual compar-
Courtney Lemons, Christine Foster, and Sarah Gregor
ison stimuli (e.g., pictures of a bed, chair, and
for their assistance with data collection and stimulus
generation. table). Second, the teacher delivers an auditory
Addresscorrespondence toJames E.Carr,Department sample stimulus (e.g., ‘‘point to chair’’). Third,
of Psychology, 226 Thach Hall, Auburn University,
the learner engages in a response (e.g., pointing
Alabama36849(e-mail: [email protected]).
doi:10.1901/jaba.2011.44-475 to or touching one of the pictures) or is
475
476 LAURA L. GROW et al.
prompted to respond. Fourth, the teacher trial format and introducing increasingly diffi-
provides differential consequences for correct cult discriminations over time. The rationale
and incorrect responses. This example of iden- behind this approach is to break down the
tifying an object from an array after hearing conditional discrimination into multiple, easier
its name is commonly referred to as receptive steps and gradually increase the difficulty as the
labeling or receptive identification. learner acquires simpler discriminations. A
Accurate responses during conditional dis- graphical depiction of how the simple-condi-
criminations require several prerequisite skills tional method can be applied to teaching a
(McIlvane, Dube, Kledaras, Iennaco, & Stod- three-stimulus array receptive labeling program
dard, 1990). Learners must observe and is shown in Figure 1. Steps 1, 2, and 6 consist
differentially respond to comparison stimuli of teaching simple discriminations in isolation
such as a visual array of pictures or objects. in a massed-trial format. Simple discrimination
Learners must also attend and differentially training in isolation does not necessarily target
respond to various sample stimuli that are or require any of the prerequisite skills to
presented across teaching trials. Learners should complete conditional discriminations (e.g.,
attend to the sample stimulus and subsequently attending to the auditory sample stimulus).
observe and respond to the comparison stimuli Steps 3 and 4 involve simple discrimination
(i.e., a successive discrimination). training in the presence of a distracter stimulus.
In a recent Internet survey, Love, Carr, It should be noted that the distracter stimuli
Almason, and Petursdottir (2009) assessed a used in Steps 3 and 4 eventually function as a
number of EIBI program practices and identi- discriminative stimulus (S+) during the simple-
fied two common approaches to teaching conditionalmethod.Forexample,thedistracter
conditional discriminations: the simple-condi- stimulus in Step 3 later functions as the S+ in
tional and conditional-only methods. The Step4.ComparedtoSteps1and2,Steps3and
survey respondents (EIBI program supervisors) 4 involve a more difficult discrimination that
reported implementing the simple-conditional requires attending and differentially responding
method most often (37% of respondents) to the visual comparison stimuli. However, the
whereasslightlyfewerserviceprovidersreported learner is not required to attend to the auditory
using the conditional-only method (32% of sample stimulus because it remains the same
respondents). Other respondents (31%) report- across the massed trials. Steps 5, 7, 8, and 9
ed implementing either the simple-conditional involve either two- or three-stimulus array
method or the conditional-only method de- conditionaldiscriminationsinwhichthelearner
pending on the specific repertoire of the child. must attend to both the auditory and visual
Given that most EIBI curricular manuals stimuli to access reinforcement for correct
recommend the simple-conditional method responding.
(e.g., Leaf & McEachin, 1999; Lovaas, 2003; In her discussion of stimulus control tech-
Maurice, Green, & Luce, 2001), we were sur- nology,Green(2001)notedthatanindividual’s
prised that EIBI program supervisors reported history with procedures like the simple-condi-
using the conditional-only method almost as tional method may promote faulty stimulus
often as the simple-conditional method. control during the final steps of conditional
The simple-conditional method is based on discrimination training, particularly for recep-
procedures described by Lovaas (2003) for tive labeling programs (i.e., auditory-visual
teaching receptive labeling and matching in conditional discriminations). During simple
EIBI programs. This method involves training discrimination training in isolation (i.e., Steps
component simple discriminations in a massed- 1,2,and6),incidentallearningmayoccursuch
RECEPTIVE LABELING 477
Figure 1. Visual depiction ofthree trialsduring each step ofthe simple-conditional method.
that the learner observes the auditory discrim- without attending to the specific auditory
inative stimulus and the correct visual stimulus stimulus (oreven thevisual stimulus)bysimply
and relates those stimuli with each other; repeating the same response that was reinforced
however, the skill is not directly taught or in the preceding trial. The discrimination in
required(McIlvaneetal.,1990).Thus,alearner Steps 3 and 4 is made more difficult by
couldrespondcorrectlyduringSteps1,2,and6 requiring differential responding to the visual
478 LAURA L. GROW et al.
comparison stimuli, but attending to the cause prior presentations of auditory stimuli
auditory sample stimulus is not yet required. were superfluous to the reinforcement contin-
Collectively, Steps 1 through 4 may promote gency. As a result, the visual stimulus present
overselectivity to the visual component of the during either response prompting or reinforcer
antecedent stimuli by establishing a history of delivery in the preceding trial may come to
reinforcementforrespondingtothesamevisual influence selection responses.
comparison stimulus without requiring attend- Other error patterns may occur during the
ing to the auditory stimulus. Thus, the visual simple-conditional method due to the arrange-
comparison stimulus may control subsequent mentofthecomparisonstimuliduringtraining.
responding rather than the auditory stimulus More specifically, the majority of steps in the
and corresponding visual stimulus together, simple-conditional method include an array of
producing faulty stimulus control. only two comparison stimuli, which may result
There is some evidence that faulty sources of in several error patterns. Onesuch error pattern
stimulation may exert control over responses as is position bias, in which the learner reliably
afunctionofexposuretothesimple-conditional selects the stimulus in either the left or right.
method. Lovaas (2003) described several error The schedule of reinforcement (i.e., variable-
patterns that commonly arise during receptive ratio [VR] 2) associated with many types of
labeling programs. Two types of error patterns, error patterns during a two-stimulus array
termed win-stay responses, may result from a discrimination procedure may support the
history of the early steps of the simple- maintenance of those error patterns over time
conditional method. Molar win-stay responses, because the schedule is denser than arrange-
characterized by a disproportionately high per- ments with a larger array of stimuli (Kangas &
centage of responses to the particular visual sti- Branch, 2008; MacKay, 1991).
mulus that served as the S+ in the preceding In contrast to the simple-conditional meth-
acquisition step, might occur during the od, in the conditional-only method (described
transition from simple discrimination training by Green, 2001), component simple discrimi-
ofaparticularstimuluswithdistracterstoeither nations are not targeted prior to conditional
simple discrimination training with a different discrimination training. Rather, all stimuli
stimulus or conditional discrimination training (usually at least three) are presented and
(e.g., transitioning from Step 3 to Step 4). targeted as a conditional discrimination from
Molar win-stay responses likely result from (a) the onset of intervention. For example, the
an immediate reinforcement history involving a experimenter presents three comparison stimuli
particularvisualstimulusand(b)theavailability andirregularlyalternatespresentingoneofthree
of thatstimulus as a responseoption during the corresponding auditory sample stimuli across
subsequent teaching step. session trials. The conditional-only method is
The early steps of the simple-conditional identical to Step 9 of the simple-conditional
method may also promote molecular win-stay method depicted in Figure 1. The rationale
responses that involve responding to the same behind this procedure is to begin with a
visual stimulus that was targeted in the procedurethatrequiresthenecessaryrepertoires
preceding trial, regardless of the presented needed to respond correctly (i.e., attending and
sample stimulus in the current trial. Because differentiallyrespondingtothesampleandcom-
the auditory discriminative stimulus remains parison stimuli). Furthermore, individuals may
unvaried in Steps 1 through 4, the learner may be less likely to engage in consistent error pat-
ignore the auditory sample stimuli in subse- terns (e.g., position biases, win-stay responses)
quent conditional discrimination training be- duringtheconditional-onlymethodthanduring
RECEPTIVE LABELING 479
the simple-conditional method because the conditionalmethod,theconditional-onlymeth-
schedule of reinforcement for a particular od may promote appropriate stimulus control
error pattern is thinner in the conditional- during conditional discrimination training and
only method. An important difference between may decrease the likelihood of error patterns
the simple-conditional and conditional-only that interfere with acquisition. To date, no
methods is the arrangement of the sample and published studies have compared the relative
comparison stimuli during training. That is, effectiveness and efficiency of the simple-
multiple sample and comparison stimulus conditional and conditional-only methods for
pairs are targeted in the same teaching session teaching conditional discriminations. There-
from the onset of training in the conditional- fore, the purpose of the current study was to
only method, whereas the numbers of sample compare the relative utility of the simple-
and comparison stimuli are gradually increased conditional and conditional-only methods for
acrossteachingsessionsinthesimple-conditional teaching receptive labeling to children with
method. ASD.
Gutierrez et al. (2009) conducted one of the
first studies to evaluate the impact of different METHOD
types of simple discrimination training on
Participants and Setting
subsequent conditional discrimination learning
Three children with a diagnosis of an ASD
in applied settings. Three children with an
participated in the study. Erin was a 7-year-old
autism spectrum disorder (ASD) were taught
girl who had been diagnosed with pervasive
toidentifyanumberofstimulireceptively.Half
developmental disorder (not otherwise speci-
of the stimuli were taught first using simple
fied). She spoke in full sentences and indepen-
discrimination training in isolation. After
dently completed most age-appropriate daily
mastery, each of the stimuli was targeted in
living skills. Prior to the study, she often
the presence of a distracter stimulus. The other
displayed faulty stimulus control during recep-
half of the stimuli were trained in a simple
tive labeling programs in her early intervention
discrimination format in the presence of
program. She had extensive exposure (approx-
distracter stimuli from the onset of training.
imately 3 years) to both teaching methods
Following both training methods, the previous-
evaluated in the study. Sessions were conducted
ly taught component simple discriminations
in a room converted into a work area in Erin’s
were targeted in a conditional discrimination home.
format. The learner acquired the stimuli in Shane was a 4-year-old boy who had been
fewer sessions when the stimuli were taught in diagnosed with autistic disorder. He communi-
the presence of distracter stimuli (i.e., without cated using gestures and several spoken words
isolation training). These results may provide (e.g., pretzels, juice, water) and needed assis-
some preliminary evidence that Steps 1, 2, and tance to complete several age-appropriate daily
6 of the simple-conditional method may not living activities. He had a brief history (approx-
build necessary prerequisites for responding imately 6 months) with the simple-conditional
accurately during conditional discrimination method in his preschool program prior to the
training or enhance future conditional discrim- study. Sessions were conducted in an unused
ination learning. room in Shane’s home.
As mentioned previously, the conditional- Devin was a 4-year-old boy who had been
only method is a widely used procedure for diagnosed with autistic disorder and disruptive
teaching receptive labeling in EIBI programs behavior disorder (not otherwise specified). He
(Love et al., 2009). Compared to the simple- communicated using three- to four-word utter-
480 LAURA L. GROW et al.
ances. He had a brief history (approximately auditory sample stimulus. For each trial,
3 months) with the blocked-trial procedure observers also collected data on the comparison
(described in the Discussion section) and the stimulus that the participant selected and its
conditional-only method at his early interven- location in the stimulus array.
tion clinic prior to the study. Sessions were The primary dependent measure was the
conductedin a smalltreatmentroom in aclinic numberofsessionsrequiredtomeetthemastery
setting. criteria for the three-stimulus array receptive
Inclusion for the study required that partic- labeling program in each condition. The
ipants (a) exhibited little or no severe problem mastery criteria in Steps 1 through 8 of the
behavior, (b) tolerated physical contact, (c) simple-conditional method required the partic-
displayed a matching repertoire (evaluated via ipants (a) to emit a correct independent
the Assessment of Basic Learning Abilities; response for eight of the nine trials in the
Martin & Yu, 2000), and (d) had goals in their sessionand(b)torespondaccuratelyduringthe
educationplansthatinvolvedreceptivelabeling. first presentation of each stimulus in the nine-
trial session. The masterycriterionforStep 9of
Materials
the simple-conditional method and the condi-
Stimuli(i.e.,picturesofobjects)wereprinted
tional-only method was three consecutive
on sheets of paper (8.5 in. [21.6 cm] by 11 in.
sessions with 100% correct independent re-
[27.9 cm]) and placed in clear page protectors
sponses.
to generate a trial sheet. The experimenter
Asecondindependentobservercollecteddata
placed a dark-colored sheet on top of each trial
on several learner responses and aspects of the
sheet (a) to prevent the participant from
stimulus arrangement, including independent
viewing the visual comparison stimuli prior to
and prompted correct responses, the location of
thedeliveryoftheauditorysamplestimulusand
thefirstresponseofeachtrial,thespecificvisual
(b) to provide an opportunity for the partici-
stimulus associated with the first response on
pant to complete an observing response (de-
each trial, and observing responses. An agree-
scribed in more detail below).
ment was defined if both observers coded (a) a
Dependent Variables, Measurement, and correct, prompted,or no response; (b) thesame
Interobserver Agreement visual stimulus for the first response in each
Apaper-and-pencilmethodwasusedtoscore trial; (c) the same location of visual stimulus
responses during each trial of a nine-trial selected;and(d)theoccurrenceoftheobserving
session. Observers scored a correct independent response. A disagreement was coded during
response if the participant pointed to the S+ trials in which observers scored any of the
within 5 s of the presentation of the auditory responses differentlyfromeachother.Point-by-
stimulus without errors or experimenter-deliv- point agreement was calculated by dividing the
ered prompts. Observers scored a prompted number of agreements in a session by the
correctresponseiftheparticipantpointedtothe number of agreements and disagreements (i.e.,
S+ within 5 s of an experimenter-delivered nine) and converting the proportion to a
prompt. The data collectors scored no response percentage. Across all evaluations for Erin,
if the participant did not point to a stimulus interobserver agreement was assessed during
within 5 s after the presentation of the auditory 37% of sessions, and mean agreement was 98%
stimulus. The data collectors scored an observ- (range,67%to100%).ForShane’sevaluations,
ing response when the participant oriented his agreement was assessed for 35% of sessions
orhereyestowardeachstimulusinthearrayfor and averaged 97% (range, 89% to 100%). For
approximately 1 s prior to the delivery of the Devin’s evaluations, agreement was assessed
RECEPTIVE LABELING 481
Table 1
StimuliTaught During Each Evaluation
Participant
Evaluation Conditionalonly Simple-conditional
Erin
1 aardvark,gazelle,hedgehog bison,lemur,warthog
2 crane,elk,squid newt,sloth,yak
3 Asia,Australia,S.America Africa,Antarctica,Europe
Shane
1 F,J,M(lettername) B,S,T(lettername)
2 Africa,Antarctica,Europe Asia,Australia,S.America
3 D,K,L(lettersound) G,H,R(lettersound)
Devin
1 bathing,coloring,dancing catching,giving,sitting
2 C,G,O(lettername) M,V,W(lettername)
during 32% of sessions and averaged 97% function of the teaching methods used rather
(range, 78% to 100%). than characteristics of the stimulus sets.
Training Sets Procedure
A training set was comprised of three stimuli Reinforcer identification. A paired-stimulus
(i.e., three auditory and corresponding visual preference assessment (Fisher et al., 1992) was
stimuli). A stimulus was included in the conducted with items suggested by either the
training set if the participant responded with participant’sprimarybehaviortherapist(Devin)
no greater than 33% accuracy during baseline or their parents (Erin and Shane) on the
probes (described below). Stimuli were selected Reinforcer Assessment for Individuals with
based on the participants’ goals in either their Disabilities (Fisher, Piazza, Bowman, & Amari,
individualized education plans or EIBI pro- 1996)toidentifyahierarchyofpreferreditems.
grams.Foreachevaluation,onetrainingsetwas ForDevinandShane,fooditemswereincluded
assigned to the simple-conditional and condi- only in the paired-stimulus preference assess-
tional-onlymethods.Thatis,sixstimuliintotal ment. For Erin, the paired-stimulus prefer-
were taught during each comparative evalua- ence assessment was conducted with activities
tion.Thespecificstimulitaughtinthestudyare (e.g., board game). We also conducted a brief
displayed in Table 1. multiple-stimulus without replacement prefer-
We attempted to equate the training sets by ence assessment (MSWO; DeLeon & Iwata,
selecting similar stimuli for each evaluation. In 1996) prior to each session with the top four or
addition,thestimuliweregroupedsuchthatthe fiveitemsthathadbeenidentifiedinthepaired-
auditory stimuli contained the same number of stimulus preference assessment in an attempt to
syllables and were as distinct as possible. One control for potential fluctuations in preference
exception to this occurred in Devin’s second across sessions.
evaluation. Similar visual stimuli were targeted Baseline probes. Nine-trial baseline probes of
in the training set because Devin had a history relations among stimuli were conducted to
of incorrect responses with this type of identify target stimuli for the subsequent
discrimination. Continents were targeted dur- evaluations. During baseline, an array of three
ing Erin’s and Shane’s second evaluations, and pictureswaspresentedtotheparticipant,andhe
those stimuli were counterbalanced across or she was instructed to emit an observing
participants to ensure that outcomes were a response (i.e., turn over the dark-colored sheet
482 LAURA L. GROW et al.
to expose the trial sheet). The purpose of this token economies; therefore, Erin had the
response was to facilitate the observation of the opportunity to exchange the stickers for backup
visual comparison stimuli. If the participant reinforcers (i.e., the items identified in the
did not observe the comparison stimuli after MSWO) after she had accumulated 20 stickers.
the sample was presented, the experimenter When given the opportunity to make an
prompted observing to each comparison stim- exchange, Erin was given a choice between
ulus (e.g., pointing to the stimuli, tapping near selecting an activity and playing for 5 min or
the stimuli) until it observation occurred. Next, savingtheactivitytimeandaddingittoafuture
the appropriate auditory stimulus (e.g., ‘‘point break.
to lemur’’) was presented and the participant Simple-conditional method. The simple-con-
was given a 5-s opportunity to respond. The ditional method was based on procedures
auditorysamplestimulusandpositionoftheS+ described by Lovaas (2003). The general
in the comparison array were rotated across teaching procedure involved a series of nine
trials in the manner recommended by Green steps (see Figure 1). Steps 1, 2, and 6 involved
(2001). Regardless of whether the response was simple discrimination training in isolation for
correct or incorrect, the experimenter removed thethreestimuliinthetrainingset.ForSteps1,
the stimuli and did not provide differential 2, and 6, the experimenter repeatedly presented
consequences for selection responses. The one sample and one comparison stimulus (i.e.,
experimenter retained stimuli if accuracy was one S+) in each session. Steps 3 and 4 entailed
33% or lower during the baseline probe. simple discrimination training in the presence
Generalteachingprocedure.Asinbaseline,the of a nontarget distracter stimulus. During Steps
experimenter initiated a trial by presenting the 3 and 4, the experimenter repeatedly presented
comparison stimuli and prompting the partic- one sample stimulus and two comparison
ipant to complete an observing response. Next, stimuli (i.e., one S+ and one S2) in each
the experimenter presented the auditory sample teachingsession.TheS2inStep3servedasthe
stimulus. If the participant made an error or S+inStep4,andtheS+inStep3functionedas
did not respond within 5 s, the experimenter the S2 in Step 4. Steps 5, 7, and 8 included a
initiated a least-to-most prompt hierarchy two-stimulus array conditional discrimination
(Horner & Keilitz, 1975) that included two in which both visual stimuli functioned as the
levelsof modelprompts anda physicalprompt. S+andS2acrosstrialsinonesession.ForSteps
The less intrusive model prompt involved the 5, 7, and 8, the experimenter presented one of
experimenter pointing within 3 in. (7.6 cm) of two sample stimuli, which were irregularly
the correct visual stimulus. The more intrusive alternated, and the two corresponding compar-
model prompt involved the experimenter ison stimuli in each session. Step 9 consisted of
pointing within 1 in. (2.5 cm) of the correct thepresentationofthreestimulithatfunctioned
stimulus. Physical guidance involved the least as both theS+ and S2 in a session. Thatis, the
amount of hand-over-hand guidance necessary experimenter presented one of three sample
to ensure a correct response. The experimenter stimuli that were irregularly alternated across
simultaneously presented the auditory sample trials and the three corresponding comparison
stimulus with all prompts. Contingent on stimuli in each session.
correct independent responses during teaching For Steps 1, 2, 6, and 9, we semirandomly
trials, the experimenter delivered enthusiastic rotatedtheS+amongtheleft,middle,andright
praise and a small piece of food (Shane and positions. For Steps 3, 4, 5, 7, and 8, we
Devin) or one sticker (Erin). Erin had an semirandomly rotated the S+ between the right
extensive history (approximately 3 years) with andleftpositions.Thecomparisonstimuliwere
RECEPTIVE LABELING 483
presented in an array of two because counter- Due to the transience of auditory sample
balancingtwostimuliacrossthreepositionsina stimuli, the auditory stimulus was repeated
manner that is consistent with procedures every 2 s following Erin’s observing response
described by Green (2001) was difficult to (Green, 2001) until a response occurred or 5 s
arrange in a nine-trial session without targeting elapsedwithnoresponse.Inaddition,weadded
a particular stimulus in an uneven manner an error-correction procedure to increase the
across positions. In a nine-trial session with an likelihood that Erin responded to the correct
array of two comparison stimuli, a given stimulus and to establish a history of reinforce-
stimulus was disproportionately targeted in the ment for responses to the correct stimulus
left and right positions in one teaching session. (Rodgers & Iwata, 1991; Smith, Mruzek,
For steps that included an array of two stimuli Wheat, & Hughes, 2006). If an error occurred,
(Steps 3, 4, 5, 7, and 8), we developed two theexperimenterpromptedthecorrectresponse
different stimulus presentations to target each and immediately re-presented an identical trial.
stimulus proportionately in the left and right This process was continued until a correct
positions over the course of two sessions. independent response occurred. Correct inde-
Conditional-only method. The procedures pendent responses during error correction
were identical to Step 9 of the simple- resulted in the delivery of a sticker.
conditional method. That is, a three-stimulus Most-to-least prompting. During Evaluations
array conditional discrimination was targeted 2 and 3 for Shane, the experimenter changed
from the onset of training. The S+ irregularly the prompting procedure from least-to-most
alternated among the left, middle, and right prompting to most-to-least prompting for two
positions. The presentation of each of the reasons. First, low levels of accuracy led to an
sample stimuli was rotated based on procedures overall reduction in the number of reinforcers
recommended by Green (2001). earned during the session, which appeared to
Additional procedures. In some cases, the evoke problem behavior (e.g., aggression and
simple-conditional and the conditional-only disruption). A prior functional analysis from
methods were insufficient for teaching the Shane’s EIBI program indicated that his
training sets. In those situations, we imple- problem behavior was maintained by access to
mentedadditionalprocedures,andtheselection foodandtoys(i.e.,positivereinforcementinthe
ofthoseprocedureswasbasedonwithin-session form of tangible items). Second, Shane allocat-
patterns of responses during training. edahigherproportionofresponsestoparticular
Repeated auditory stimulus presentations, addi- comparison positions during teaching, which
tional observing response, and error correction. may have interfered with the acquisition of the
Based on error patterns in the simple-condi- conditional discrimination. During the first
tional method during Evaluations 2 and 3 for session of most-to-least prompting, the exper-
Erin, we hypothesized that her responses were imenter physically guided Shane to select the
influenced by the specific visual comparison correct comparison stimulus. Next, the exper-
stimulusthatwastargetedineithertheprevious imenter interspersed least-to-most probes after
phase or trial. Following the initial delivery every two most-to-least prompting sessions (a)
of the sample stimulus, Erin was instructed to to determine if prompts could be faded during
emit a vocal observing response (i.e., repeat the most-to-least prompting sessions and (b) to
auditory sample stimulus) to ensure that she assess levels of independent responses across
attendedtotheauditorysamplestimulus.Next, teaching sessions. The prompt that occasioned
the experimenter presented the comparison the highest proportion of correct responses
stimuli and re-presented the sample stimulus. during the least-to-most probe was used during
484 LAURA L. GROW et al.
the two subsequent most-to-least prompting mentationofthefollowingduringeachtrial:(a)
sessions. During least-to-most probes, observers each type of prompt, (b) the order in which
collected data on the same dependent variables prompts occurred, (c) the response interval
as those noted for the least-to-most sessions in followingprompts,(d)consequencesforcorrect
the prior phase. Thus, observers collected data and incorrect responses, and (e) the procedure
onindependentresponsesthatwerecomparable to facilitate an observing response. Observers
across phases. collected additional integrity measures for Erin
Alternative observing response. During Shane’s during Evaluations 2 and 3. These included the
second evaluation, he rarely attended to the experimenter’s correct implementation of (a)
visual stimuli without repeated experimenter the procedure to facilitate the vocal observ-
prompts. To enhance independent attendance ing response, (b) additional deliveries of the
to the visual comparison stimuli, the experi- auditory sample stimulus, and (c) the error-
menter prompted an alternative observing correction procedure. Observers also collected
response prior to presenting the sample and treatment integrity measures for Shane. These
comparison stimuli. The experimenter present- included the experimenter’s correct implemen-
ed the dark-colored piece of paper on top of a tation of (a) the alternative observing response
trial sheet in an upright position at Shane’s eye (Evaluation 2) and (b) a most-to-least prompt-
level. This presentation is different from the ingprocedure(Evaluations2and3).Atrialwas
original format in which the experimenter scored as correct if all experimenter responses
presented the trial sheet laid flat on the table. were implemented as specified by the research
A least-to-most prompting procedure was used protocol. When calculating the integrity mea-
to teach Shane to pull the dark-colored paper sures, a trial was scored as incorrect if any
positioned in front of the trial sheet to expose treatment integrity measure was scored as
the visual comparison stimuli. incorrect by either observer. The percentage of
Maintenance. The experimenter conducted correctly implemented trials was calculated by
baseline probes (identical to those described dividingthenumberofcorrecttrialsbythetotal
above)3weeksaftermasteryofeachtrainingset. number of trials and converting the propor-
The purpose of these probes was to assess tion to a percentage. Treatment integrity was
whether participants’ acquisition of the three- assessed during 37% of sessions and averaged
arrayconditionaldiscriminationwasmaintained. 98% (range, 78% to 100%) for Erin. For
Because Shane did not meet mastery criteria for Shane, treatment integrity was assessed during
the stimuli trained using the simple-conditional 35%ofsessionsandaveraged97%(range,78%
method in the third evaluation, we did not to 100%). For Devin, treatment integrity was
conduct a maintenance probe for these stimuli. assessed during 32% of sessions and averaged
97% (range, 78% to 100%). Point-by-point
Design interobserver agreement was calculated for all
An adapted alternating treatments design treatment integrity measures and averaged at
(Sindelar, Rosenberg, & Wilson, 1985) was least 97% for each participant.
usedtocomparediscrimination learningduring
the simple-conditional and conditional-only Error Analysis
methods. Two or three comparative evaluations We conducted several error analyses during
were conducted for each participant. phases that required additional intervention
components to meet the mastery criterion. We
Treatment Integrity reviewed the data sheets and retrieved informa-
Toassesstreatmentintegrity,anindependent tionthatallowedadetailedanalysisofresponses
observer recorded the experimenter’s imple- within each teaching session. An analysis of