SingleSubject Designs and the Field of Deafblindness

1
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

2
Sociopolitical Context for this Study

• NCLB
• What Works Clearinghouse (WWC)
• Response from the CEC, APA and others

3
Experimental Research in Education

• 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.

4
Development of the field of deafblindness

• Within the development of the field of
  deafblindness in the United States, the 1964-65
  rubella epidemic, which preceded Public Law
  94-142, 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).

5
Rationale for the Study

• 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

6
Research Questions

• 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?

7
Research Questions

• What types of interventions and educational
  practices were identified within these studies?
• Are there any patterns of replication across
  studies that have been conducted?

8
Methodology

• published in peer reviewed journals
• included people who were deafblind as
  participants (children or adults)
• focused on some type intervention or teaching
  practice

9
Databases

• DB-LINK
• PsycINFO
• Academic Search Premier
• ERIC

10
Original Search Terms

• 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.

11
Inclusion/Exclusionary Criteria

• 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.

12
Evaluation form

• A rating form was created based upon the CECs
  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.

13
Inter-rater Reliability

• 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 .

14
Additional search terms applied after study
published

• Additional key author searches were applied
  post-publication (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.

15
Types of Studies That Emerged

• Behavior n28
• Communication n 23
• Daily Living Skills n 21
• Vocational n5
• Total Participants 143 Age range 8 months- 38
  yrs.

16
Categories Within Behavior n 28Published range
1969-1998
17
Settings for Behavioral Studies

• Residential Schools for the Blind/Deaf 9
• Self-contained classrooms 8
• ICFMR 6
• Group home 3
• Workshop 3
• Supported living 1
• Training event 1

18
Types of Behavioral Interventions Based on Least
Restrictive Model (Mori Masters, 1980)
19
Frequencies of Intervention Types
20
Other considerations Behavioral

• 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.

21
CEC Quality Indicator Social Validity

• 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).

22
Recommendations for Practice and Research from
Behavioral Studies

• It is paramount to identify the variables that
  maintain self-injurious, 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.

23
Summary from Behavioral Studies and Future
Questions

• 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.

24
Communication Studies n 231985-2006
25
Analysis of Communication Forms Functions by
Intervention Types Examples
26
Communication Studies Settings

• 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
• Childs home 1

27
Other considerations Communication

• 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).

28
CEC Quality Indicators Generalization and Social
Validity

• Thirteen of the 23 studies included
  generalization measures.
• Eight of the 23 formally measured social validity.

29
Recommendations for Practice and Research-
Communication Studies

• Based upon replicated intervention within
  multi-component intervention studies, there is
  evidence that intensive support and training for
  communication partners (peers, para-educators,
  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.

30
Summary from Communication Studies and Future
Questions

• 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.

31
Daily Living Skills Studies n211980-2004
32
Settings for Daily Living Studies

• 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 self-contained class in a
  typical school.

33
Other considerations for DLS

• 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)

34
CEC Quality Indicators Generalization and Social
Validity

• 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.

35
Recommendations for Practice Research from DLS

• 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.

36
Vocational Studies 1989-1998 n 5

• 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
  on-task 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.

37
Vocational Independent Variables

• One set of researchers used an alternating
  treatment design to compare an adolescents 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)

38
Patterns in the Research

• 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.

39
Limitations of This Study

• 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

40
Descriptors of people who are deafblind in the
literature examples

• 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

41
Framework for measuring practice

• 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.

42
More criteria for evidence-based practice

• 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)

43
Other Types of Experimental Designs That May Lend
Support

• 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).

44
Implications for Future Research

• 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.