Transcript Single-Subject Designs and the field of deafblindness

Single-Subject
Designs and the Field
of Deafblindness
Amy T. Parker, M.S.S.W.
Roseanna Davidson, Ed.D.
Devender Banda, Ph.D., BCBA
Texas Tech University
Sociopolitical Context for this Study
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NCLB
What Works Clearinghouse (WWC)
Response from the CEC, APA and others
Experimental Research in Education
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Tawney and Gast (1984) refer to the
“missing era of empiricism” in the broader
development of field of special education.
They further describe the development of
the special education system as one
created by external political forces that led
to a rapid need for teacher preparation
training programs at colleges and
universities.
Development of the field of
deafblindness
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Within the development of the field of
deafblindness in the United States, the 1964-65
rubella epidemic, which preceded Public Law 94142, and created an immediate need for
practitioners and educators across all service
systems to meet the diverse needs of a
population of deafblind children unlike any that
had been served in U.S. educational service
systems in the past (Enerstvedt, 1996; Spar,
1972).
Rationale for the Study
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A heterogeneous population
Challenges of producing, replicating research with
low incidence population
Uniqueness of the field on the cusp of
blindness, deafness and multiple disabilities
Discovery of existing evidence for current
practitioners and families
Platform for future research efforts
Research Questions:
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What types of single-subject design
studies, published in peer reviewed
journals, were conducted with participants
(adults and children) who are deafblind
from 1965-2006 in the fields of education
and rehabilitation?
Research Questions:
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What types of interventions and
educational practices were identified
within these studies?
Are there any patterns of replication
across studies that have been
conducted?
Methodology
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published in peer reviewed journals
included people who were deafblind as
participants (children or adults)
focused on some type intervention or
teaching practice
Databases
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DB-LINK
PsycINFO
Academic Search Premier
ERIC
Original Search Terms
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“deaf-blind studies”;
“dual-sensory impairment studies”
“research in deaf-blindness”
“congenital rubella syndrome”
“Usher syndrome”
For DB-LINK the terms “study”, “research”,
and “design” were specifically applied to its
database.
Inclusion/Exclusionary Criteria
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Studies that were correlational, empirically
descriptive, or qualitative were not
considered in this examination. The fourth
and final criterion for examining studies
was that they employ single-subject design
methodology and not some other type of
non-randomized group designs.
Evaluation form
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A rating form was created based upon the
CEC’s quality indicators for single-subject
design methodology and included the
variables of: participant descriptions,
settings, study design, independent
variables, dependent variables, social
validity and generalization.
Inter-rater Reliability
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The first and third author independently
rated 30% of the identified sample studies.
Inter-rater agreement was calculated by
dividing the number of agreements by the
number of agreements plus disagreements
and multiplying by 100. The inter-rater
agreement was 100 %.
Additional search terms applied after
study published
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Additional key author searches were applied postpublication (Parker, Davidson & Banda, 2007).
Ancestral searches of authors, continued
communication with DB LINK Librarians and
discussions with field leaders have lead finding
additional articles.
Hidden nature of deafblindness as a disability
within the literature.
Types of Studies That Emerged
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Behavior: n=28
Communication: n= 23
Daily Living Skills: n= 21
Vocational: n=5
Total Participants = 143;
Age range 8 months- 38
yrs.
ages 0-10
age 11-21
22 +
Categories Within Behavior n = 28
Published range 1969-1998
Self-injurious behavior
studies n = 14
Aggressive behavior
studies: n = 6
Non-compliant behavior
Studies: n = 8
Participant Age Range:
5-25 yrs; M = 15.14 yrs.
Total part. = 22
Participant Age Range:
6-25 yrs; M = 14 yrs.
Total part. = 7
Participant Age Range:
6-25 yrs.; M = 14.86 yrs.
Total part. = 8
Settings for Behavioral Studies
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Residential Schools
for the Blind/Deaf = 9
Self-contained
classrooms = 8
ICFMR = 6
Group home = 3
Workshop = 3
Supported living = 1
Training event = 1
SC Class
RSB/D
ICFMR
Grp. Hm.
Wkshop
Other
Types of Behavioral Interventions: Based on
Least Restrictive Model (Mori & Masters, 1980)
Least Intrusive
Interventions- n = 24
More Intrusive- n = 7
Most intrusive- n = 10
Aversive- n = 2
FCT; NCR; CR (food,
praise); DRO, DRI, DRA,
DRL; Token economy
Response blocking, facial
screening; spearmint scent
in air; time-out
Temporary restraint of
hands; helmet; splints;
overcorrection; Rx
Water mist sprayed in the
face
Frequencies of Intervention Types
DRO/I/A/L
CR-fd/pr.
Res/Equi
NE TO
FCT
Resp. B.
H2O mst.
face scr.
scent
token
over cor.
Other considerations: Behavioral
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Twelve of the 27 studies conducted a FBA before
intervening.
Ten of the 27 studies reported to offer training on
intervention procedures to teachers, staff, parents
or consumers (self-management).
Twenty of the 27 reported adaptations for
deafblind participants; the main adaptation was
the use of sign language for communication
access.
CEC Quality Indicator: Social Validity
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While most of the studies included
generalization measures, only one
behavioral study formally measured social
validity of the treatment. This study was
also one of the few studies conducted in a
community based setting (Umbreit, 1997).
Recommendations for Practice and
Research from Behavioral Studies
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It is paramount to identify the variables that maintain selfinjurious, aggressive, or non-compliant behaviors through the
application of functional behavior analysis.
Efforts of intervention, particularly for deafblind participants,
should emphasize not only response reduction but skill
acquisition (Luiselli, 1990). Aversive procedures by definition
do not teach alternative behaviors (Luiselli, 1990).
There are literature gaps for identifying interventions for
young children who are deafblind with behavioral challenges;
research conducted in more inclusive settings; and the use of
functional communication training for people who are
deafblind to reduce severe behavioral problems.
Summary from Behavioral Studies and
Future Questions:
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Twelve of the 27 studies used multiple components as a part of an
intervention package. Less intrusive interventions were partnered
with more intrusive to reduce behaviors.
Thirteen of the 27 studies used less intrusive measures (DRO, CR,
TE, FCT) alone to reduce severe behavior problems. A handful of
studies used aversive or the most intrusive as the only approach.
More analysis is needed to measure what types of combinations
were more effective.
Interventions should be replicated with measures of social validity
and in less restrictive environments.
The field of applied behavioral analysis has evolved since 1960
(Horner et. al. 2002), these studies are a reflection of that evolution
and of the history of people who are deafblind.
Communication Studies n = 23
1985-2006
Microswitch interventions
n=7
Participants age range- 8
mos.- 32 yrs. M = 18 yrs.
Participants = 9
Multi-component Training
Part. Age range- 3-35 yrs.
n = 10
Participants = 30
Dual Communication Boards Part. Age Range- 16-20 yrs.
N=4
Participants = 15
Object Symbols; Prompting:
Part. Age Range- 8; 21
N= 2
Participants = 3
Analysis of Communication Forms & Functions
by Intervention Types: Examples
Communication
Interventions
Topographies of
Communication
Behaviors
Communication
Functions
Microswitch
Interventions
Reaching; Leg
movements,
Vocalizations, Head
movements
Learn to request
preferred object,
person or action
Multi-component
Partner training
Pointing, vocalize,
reach, use words,
signs, turn-taking,
initiating
Greeting, Request
object, person or
action, Comment,
Reject
Communication Studies Settings
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Residential Schools for the
Blind/Deaf = 5
ICFMR/Nursing = 3
Self-contained class = 4
Inclusive class = 3
Community employment =
5
Supported living = 1
Day Habilitation = 1
Child’s home = 1
RSB/D
ICFMR
SC class
I class
Employ
SL
DH
Home
Other considerations: Communication
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Sixteen of the 23 studies reported some
type of training on the intervention to other
communication partners in the
environment.
Nineteen of the 23 studies reported specific
intervention adaptations for people who are
deafblind (examples: tactile overlays on
microswitch, object/tactile symbols; touch
cues; and sign language).
CEC Quality Indicators:
Generalization and Social Validity
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Thirteen of the 23 studies included
generalization measures.
Eight of the 23 formally measured social
validity.
Recommendations for Practice and
Research- Communication Studies
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Based upon replicated intervention within multi-component
intervention studies, there is evidence that intensive support
and training for communication partners (peers, paraeducators, residential support staff, teachers, parents) is
supportive of building the expressive communication skills of
deafblind people (multiple researchers, settings, locations; 30
participants)
Based upon replicated intervention, for some people with
deafblindness, working with microswitches can provide a
means for increasing requesting behaviors (multiple
researchers, settings, locations, 9 participants)
Using preferred activities, objects, and people can assist in
building meaningful communication exchanges. This was
replicated across microswitch & multi-component studies.
Summary from Communication
Studies and Future Questions:
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Assessment of replication of the IV is challenging.
Using a microswitch to develop contingency awareness and
request preferred objects, people, or action was replicated with
people who are deafblind with additional motor impairments.
Dual communication board studies (n = 4) represent true replication
of the IV within a specific context and with people who have
residual vision.
Multi-component partner studies share elements of replication in
intensive support, training and feedback to communication partners.
Each of these studies required partners to recognize and respond
to unique topographies of communication (pointing, gesturing,
orienting, using communication cards, signing, using words.)
Thematically this was replicated as an intervention practice.
More analysis is needed to assess which combinations were most
effective.
Daily Living Skills Studies n=21
1980-2004
Mobility & Physical Activity
n= 10
Participants Age Range: 14-36 y
Age M = 24.5 y
Part n= 16
Household Activities & Leisure
Activities n = 5
Participants Age Range: 13-34 y
Age M = 20 y
Part n= 8
Self-feeding & Mealtime
n= 3
Participants Age Range: 6-18 y
Age M = 10 y
Part n= 6
Toileting
n= 3
Participants Age Range: 6-31 y
Age M = 15; Part n= 11
Settings for Daily Living Studies
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Thirteen of the 21 studies
occurred in institutional
facilities.
Four of the 21 occurred in
center schools.
Three occurred in
residential schools for the
blind
One occurred in a group
home.
One occurred in a selfcontained class in a typical
school.
ICFMR
Center S
RSB
Gr.
Home
SC Class
Other considerations for DLS:
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“Mobility & movement” considered
purposeful activities in the environment as
a part of the study.
A wide varieties of assistive technology was
used in 13 of the 21 studies (examples:
robots, infared systems, lights, vibrating
prompting devices, computerized systems,
pants alerts)
CEC Quality Indicators:
Generalization and Social Validity
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Seven of the 21 measured social validity.
Often this was measured through raters
(parents & staff) viewing videotapes of
interventions and considerations of “indices
of happiness” for students.
Seven of the 21 measured generalization
across behaviors or people.
Recommendations for Practice &
Research from DLS
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All of the movement and mobility studies
were conducted with the same lead
researcher. Replicate research with
different research teams and in different
settings to establish external validity.
Examine and replicate teaching
components of other studies to establish
practice.
Vocational Studies 1989-1998; n = 5
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There were 8 participants, ages 13-38 yrs.
within this category.
Lancioni et. al., 1991 used an alternating
treatment design to measure use of a vibratory
prompting, contingent reinforcement and peer
support in different combinations to improve ontask behavior during assembly work.
Lancioni et. al. 1992 compared use of a robot
with contingent reinforcement under peer
support and alone conditions in improving % of
correct tasks in an assembly job.
Vocational Independent Variables
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One set of researchers used an alternating treatment design
to compare an adolescent’s work performance when he was
trained with a peer supporter and when he was trained
individually (Lancioni, Olivia, & Bartolini, 1990).
One set of researchers employed a withdrawal design to
measure the use of tactile prompts and object cues across
job tasks (Berg & Wacker, 1989).
In another study, modified alternating treatment design was
used to compare choice-making in vocational assessment
conditions with choice making in the actual work environment
(Parsons, Reid, & Green, 1998)
Patterns in the Research
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All studies represented interventions utilized with
deafblind people who have additional disabilities
(cognitive, developmental, orthopedic, etc.)
During the decade of 1986-1995, CRS was
reported to account for about one third of the
population of children and adults receiving
education and rehabilitation services (Riggio,
1992). That proportion was directly represented in
this research with a third of participants in the
studies identified between 1986-1995 having
CRS.
Limitations of This Study
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Breadth of age groups
Limits of search terms- missing articles
Hidden nature of people who are deafblind
Breadth of practices made true analysis of
replication difficult
Need for quantitative analysis of
components to determine more precise
replications
Descriptors of people who are
deafblind in the literature: examples
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“functional residual vision and deafness”
“congenitally deaf with functional vision
only in one eye”
“congenital cataracts with a hearing loss of
70 db”
“deaf but had minimal vision”
“multi-handicapped blind”
“deaf and partially sighted”
Framework for measuring practice:
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Well-established (Lonigan, Elbert &
Johnson, 1998; Odom et. al., 2002) for
SSD is when: n > 9 studies. (using CEC
quality methodological practices for SSD)
Emerging & effective (Odom et. al., 2003)
for SSD is when: n = 4-6 studies.
Probably efficacious (Lonigan et. al.,
1998) for SSD is when: n > 3 studies.
More criteria for evidence-based
practice:
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Is the practice operationally defined?
Is the context clearly defined?
Is the practice implemented with fidelity?
Is the practice functionally related to change in
VALUED outcomes?
Is experimental control documented across a
range of studies, researchers & participants? (n >
5 studies; > 3 researchers; > 3 geographic
locales; > or = 20 participants)
Other Types of Experimental Designs
That May Lend Support
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A small number of experimental studies found did
were not SSDs.
The significance of these larger experimental
studies is that their findings support and
contribute to the body of findings from the
communication single-subject designs for use of
object symbols, microcomputers, or assistive
technology (Mar & Sail, 1994; Rowland &
Schweigert, 2000; Schweigert & Rowland, 1992).
Implications for Future Research
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Line up the studies for like practices to examine
efficacy and true replication. Conduct quantitative
analysis (PND) of replicated variables.
Build from past research to validate emerging
practices.
Create new research based on other types of
needs within the population (Usher, CVI with
hearing impairment; CHARGE; others)
Create research with high levels of social validity
by partnering with consumers and families.