The Board of Directors of the National Association of Social Workers (NASW) in June 1984
approved the following 11 standards for clinical social workers:
- Standard 1. Clinical social workers shall function in accordance with the ethics and the
stated standards of the profession, including its accountability procedures. . . .
- Standard 2. Clinical social workers shall have and continue to develop specialized
knowledge and understanding of individuals, families, and groups and of the therapeutic
and preventive interventions. . . .
- Standard 3. Clinical social workers shall respond in a professional manner to all
persons who seek their assistance. . . .
- Standard 4. Clinical social workers shall be knowledgeable about the services available
in the community and make appropriate referrals for their clients. . . .
- Standard 5. Clinical social workers shall maintain their accessibility to clients.
. . .
- Standard 6. Clinical social workers shall safeguard the confidential nature of the
information obtained within that relationship. . . .
- Standard 7. Clinical social workers shall maintain access to professional case consultation.
. . .
- Standard 8. Clinical social workers shall establish and maintain professional offices
and procedures. . . .
- Standard 9. Clinical social workers shall represent themselves to the public with accuracy.
. . .
- Standard 10. Clinical social workers shall engage in the independent private practice of
clinical social work only when qualified to do so. . . .
- Standard 11. Clinical social workers shall have the right to establish an independent
private practice. . . . (Minahan, 1987, pp. 966-970)
Implicit in these standards is the notion that clinical social workers should be
accountable to their clients and conduct ethical practice, their goal being to improve the
quality of services. Toward this end, the standards help to establish professional
expectations that can assist social workers to monitor and evaluate clinical practice. In
particular, an interpretation of standard 2 is that clinical social workers should have
knowledge and skills from research to evaluate the effectiveness of their work (Minahan,
1987, pp. 966-967).
Approaches for using research to assist in the assessment and evaluation of clinical
practice include interviews with clients, systematic observation, use of forms and
questionnaires, content analysis of case records and taped recordings, surveys, use of
rating scales, and the collection of information before treatment begins and after
termination (Tripodi & Epstein, 1980). Because clinical social workers cannot use only
one approach to evaluate the effectiveness of work with all clients, they must have a
repertoire of available methodologies. One methodology clinical psychologists and social
workers have used is single-subject design (Barlow & Hersen, 1984; Bloom, Fischer,
& Orme, 1993; Jayaratne & Levy, 1979; Kazdin, 1992). Every clinical social worker
should be familiar with the basic notions and procedures of this methodology. Moreover,
clinical social workers can use single-subject designs to assess and evaluate as well as
to provide input for clinical decisions (Hayes, 1992).
PURPOSE
This book is an introduction to single-subject design methodology for clinical social
workers, students, and supervisors. The intent is to provide clinical social workers a
perspective on the application of the methodology and the types and levels of knowledge it
can generate to enable social workers to assess clinical problems and to evaluate
practice. However, single-subject design methodology cannot replace information obtained
in clinical interviews and observations.
The three major objectives are
- to present a basic model of single-subject design methodology and selected variations
from the model
- to show how the basic model can serve as a frame of reference for making clinical
decisions with respect to assessing and evaluating the effectiveness of practice
interventions
- to illustrate the utility of single-subject design methodology in a variety of clinical
settings.
The book refers to the term single-subject design, rather than single-case design or
single-system design, for the following reasons:
- Single-subject design was the preferred term when researchers first applied the
methodology to social work in the 1970s (see, for example, Jayaratne, 1977).
- The term subject refers to a single unit of analysis, that is, an individual, a couple,
a family, or a group. These units coincide with the client units for clinical social
workers.
- The term case is ambiguous because it can refer to more than one unit of analysis, for
example, the client and his or her family. Case, however, is preferred by psychologists
who developed the methodology in detail (see Hersen & Barlow, 1976). For purposes of
this book, case and subject are synonymous.
- Bloom et al. (1993) used single-system to refer to "one individual, group, or
collectivity" (p. 11), but their usage throughout the text appears to be synonymous
with subject or case. More over, system implies an analysis of much more than a single
unit, that is, an interrelationship among units. Single-subject design methodology does
not involve the study of interactions among units.
Authors, for example, Barlow and Hersen, (1984), Bloom et al. (1993), have adequately
explained single-subject designs in books from behavioral psychology and social work.
However, although the authors have provided a comprehensive presentation of many complex
designs, they have not distinguished between those few designs that are useful to clinical
social workers and those that are impractical. Moreover, their examples generally pertain
to behavioral psychology and often appear in applicable to much of clinical practice.
Furthermore, the authors' presentations appear to be more complex than necessary. The
authors do not adequately distinguish the levels of knowledge produced, leading readers to
believe that causal knowledge is more obtainable than it is. In addition, the authors do
not clearly show how to make inferences from single-subject designs to inform the
assessment and evaluative decisions of clinical social workers.
CLINICAL SOCIAL WORK
The following definition of clinical social work was accepted in January 1984 by the
Board of Directors of NASW:
Clinical social work shares with all social work practice the goal of enhancement and
maintenance of psychosocial functioning of individuals, families, and small groups.
Clinical social work practice is the professional application of social work theory and
methods to the treatment and prevention of psychosocial dysfunction, disability, or
impairment, including emotional and mental disorders. It is based on knowledge of one or
more theories of human development within a psychosocial context.
The perspective of person-in-situation is central to clinical social work practice.
Clinical social work includes interventions directed to interpersonal interactions,
intra-psychic dynamics, and life-support and management issues. Clinical social work
services consists of assessment; diagnosis; treatment, including psychotherapy and
counseling; client-centered advocacy; consultation; and evaluation. The process of
clinical social work is undertaken within the objectives of social work and the principles
and values contained in the NASW Code of Ethics. (Minahan, 1987, pp. 965-966)
This definition is broad and encompasses a variety of clinical services in public and
private settings; a diversity of client populations with respect to such factors as
income, race, social class, and so forth; a range of psychosocial problems; and use of
different theories and assumptions about the relationship of the person to her or his
situation.
Clinical social workers may work in mental health agencies -- hospitals, clinics,
after-care services; employee assistance programs (EAPs) for business, education,
hospitals, factories, and so on; family therapy and family counseling agencies; criminal
justice and juvenile institutional, probation, and parole facilities; child guidance
clinics; and medical and public health facilities. Clinical social workers may engage in
private practice either by themselves or in collaboration with other professionals such as
psychiatrists, psychologists, and family counselors. Overall, clinical social workers are
functioning in a number of diverse human services agencies and organizations, as well as
providing treatments or interventions (these terms are interchangeable) in private
practice arrangements.
It therefore follows that clinical social workers deal with clients who represent
different cultural and ethnic backgrounds and social classes. However, not all clinical
social workers work with a vast range of clients. Some social workers in private practice
may work exclusively with particular populations, for example, with male adolescents from
middle-income families, focusing on problems of phobias, school adjustments, family
relationships, and self-esteem. In contrast, clinical social workers employed in a mental
health clinic may work with a more diverse population. The eligibility requirements of the
agency or setting in which social workers are employed tend to define client populations.
Hence, clinical social workers in a Veterans Affairs (VA) neuropsychiatric hospital will
work with veterans from the military who have psychiatric diagnoses and with their
families; social workers in a medical hospital may work primarily with cancer patients and
their families, dealing with the realities and fears of cancer and its consequences; and
clinical social workers in an EAP may focus on individual and small group interventions
aimed at reducing stress in the workplace. Furthermore, clinical social workers in the
child welfare system may focus on specific interventions, for example, family preservation
services as provided by states such as Michigan, designed to prevent out-of-home
placements, to increase the child management skills of parents and to eliminate child
abuse and neglect; and clinical social workers may work in teams with other mental health
professionals to provide counseling when disasters occur, such as Hurricane Andrew in
southern Florida, adolescent suicide and its impact on the adolescent's schoolmates, and
public acts of homicide and the fear they generate.
Collectively, clinical social workers use different theories about personality and the
environment and about changes or the prevention of changes in knowledge, feelings,
attitudes, behaviors, skills, and interpersonal interactions. Some social workers are
eclectic and use a range of techniques depending on the client, problem, and situation.
They may use behavior modification techniques, cognitive interventions, and ego
psychological perspectives within an ecological framework. Other social workers may use
one major approach stemming from a particular theoretical point of view. For example, they
may specialize in the use of group techniques for teaching clients interpersonal skills or
they may focus on the therapeutic transaction, providing a means for their clients to
understand the dynamics of human relationships with the clinical social worker, their
families, and other significant groups.
Tasks
Much of clinical social work practice progresses through interrelated phases. These
phases or stages follow a problem-solving model that authors have incorporated into books
about social work practice (Blythe & Tripodi, 1989; Hudson & Thyer, 1987; Tripodi
& Epstein, 1980). The practice phases used by Tripodi and Epstein -- assessing the
problem and formulating the treatment, treatment implementation and monitoring, and
treatment evaluation -- are used here because they are complementary to the basic
single-subject design model of baseline, implementation, and follow-up.
In the initial phase of practice with a client, the clinical social worker typically is
involved in a number of tasks that are preliminary to the implementation of a treatment or
intervention. The social worker gathers information about the client; the source of
referral; the client's family, employment, and school history; and the nature and extent
of the problems for which the client is referred, either by self or by others in voluntary
or involuntary conditions such as mandatory treatment for child abusers or probationers.
It is especially important for the clinical social worker to determine whether he or she
can provide services appropriate to the client's problems. Hence, the social worker seeks
information to make a judgment about what the problems are and whether he or she can
engage the client in dealing with the problems. Many clients have a number of problems
related to finances, housing, and other basic needs as well as with particular forms of
illness, disease, and interpersonal communication and interactions. Hence, the clinical
social worker must set priorities to the problems and deal first with those that are more
immediately life-threatening or those that are more pressing because of environmental
constraints through the courts and other community agents of control. During this phase,
the clinical social worker uses his or her knowledge of theory, research about the
effectiveness of interventions, and experience to formulate a treatment plan in
cooperation with the client. The social worker devises a contractual arrangement, oral or
written, to represent the mutual obligations of the clinical social worker and the client
and operationalizes to the extent possible the treatment objectives and the means of
achieving them. For example, treatment objectives for a client might include the reduction
of anxiety and depression and an increase in positive interactions with his or her mother.
The intervention may involve systematic desensitization for the client and counseling
sessions with the client and his or her mother that include role plays about negative
interactions and discussion about the ways in which both individuals might increase
positive interactions.
Having decided which problems to deal with and determined an intervention plan, the
clinical social worker, during the second practice phase, attempts to implement the
treatment and to monitor compliance of the social worker and the client with the treatment
contract. The social worker implements treatment procedures and makes observations about
the degree to which the treatment is implemented as planned. Furthermore the social worker
makes judgments about the degree to which he or she should continue the treatment or
intervention procedures if the social worker and the client attain treatment objectives.
The third practice phase involves the termination of treatment as well as follow-up to
determine whether the effects of treatment, if obtained, are persistent. This is the
evaluation phase in which the clinical social worker discontinues the intervention if the
social worker and client attain the treatment objective but plan to observe any changes
that occur with the disruption of treatment. The clinical social worker may withdraw an
intervention because he or she has accomplished one objective but still work with the
client on another problem (Blythe & Tripodi, 1989). For example, systematic
desensitization might reduce a client's anxiety, and the clinical social worker may
withdraw that intervention; however, the social worker may continue to work with the
client and the client's mother through counseling and role plays to increase positive
interactions between client and mother. On the other hand, the social worker may terminate
social workerclient contacts if there are no further problems. However, the social
worker may continue services in long-term care facilities where the purpose of treatment
is not to change feelings and behaviors but to maintain the client's state of feelings and
attitudes about care.
Decisions
Clinical social workers make decisions -- answers to questions pertaining to their
major tasks -- throughout the treatment phases. In the assessment and treatment
formulation phase, the social worker answers questions such as the following:
- What is the client unit -- an individual, a couple, a family, a group, and so forth?
- What is the client unit's current status -- living arrangements, occupation or student
status, identifying demographic variables, and social and psychological assets and
deficits?
- How was the client referred to the social worker? Was the referral appropriate or should
the client have been referred else where?
- What are the client's problems and needs?
- Is the client sufficiently motivated to engage in the treatment process with the social
worker?
- Can the social worker help the client resolve his or her problems and does the clinical
social worker have in his or her repertoire a social work intervention that will meet the
client's needs?
- Can the social worker assist the client to prioritize his or her problems or needs and
can the social worker and the client agree on which problems to deal with?
- What are the treatment objectives for the designated problems? Do the clinical social
worker and the client agree with those objectives?
- Can the social worker procure information to assess the nature and severity of the
designated problems?
- Does it appear that the problem will continue and even become exacerbated without
intervention? (Questions were adapted and modified from Tripodi & Epstein, 1980, p.
12.)
Decisions in the treatment implementation and monitoring phase focus on the delivery of
the intervention, its appropriateness for the client, and whether progress occurs in
realizing the treatment objectives. The social worker answers questions such as the
following:
- Do the client, the clinical social worker, and others important for successful
implementation understand what is expected in and between treatment sessions?
- Has the social worker implemented the intervention according to professional standards
and the provisions of the treatment contract?
- Does the client appear to want to participate in the intervention plan? Is the
intervention appropriate for the particular client? If not, should the social worker use
another intervention?
- Are there any barriers to implementation? Can the social worker overcome these barriers?
- Should the social worker revise the initial assessment?
- If implementation of the intervention is inadequate, should the social worker modify the
intervention?
- Has there been progress in achieving the treatment objectives? If the social worker and
the client have attained treatment objectives, should they terminate the treatment (or
intervention)?
- If the social worker terminates the intervention, should he or she plan to follow-up the
client to determine whether the attainment of treatment objectives persists?
(Questions were adapted and modified from Tripodi & Epstein, 1980, p. 99)
The final phase of evaluation continues with questions about the achievement of
treatment objectives, termination, and follow-up. The second and third phases are
interrelated, but the third phase focuses more on the degree to which the intervention has
been effective and continues to be effective. However, the clinical social worker also
uses this phase to verify the initial assessment and possibly to uncover new problems that
originally were not manifest. The social worker then makes decisions based on responses to
questions such as the following:
- To what extent have the social worker and the client achieved the treatment objectives?
- If they have not achieved the treatment objectives, are there any discernible reasons
why not? Was the treatment appropriate for the client?
- Was termination appropriate? Is there any evidence of client relapse?
- Has client progress persisted in follow-up with the withdrawal of the intervention?
- What level of knowledge did the intervention produce with respect to its relationship to
the client's problems? Will this knowledge be useful in the work with other clients?
- Did new problems emerge during the follow-up period?
- Should the social worker reinstitute the intervention (or another one) for the client?
(Questions were adapted and modified from Tripodi & Epstein, 1980, pp. 161-162.)
SINGLE-SUBJECT DESIGN METHODOLOGY
Single-subject design methodology includes the specification and measurement of
variables that indicate the client's problems; the systematic recording of the extent and
severity of the problems before the social worker offers interventions; the systematic
recording of the extent of the problems during and after the treatment or intervention;
the use of designs, graphic procedures, pattern analysis, or statistical analysis; and a
conception of levels of knowledge and necessary evidence to make inferences about the
attainment of knowledge levels. In its simplest expression, the complete basic model
involves three successive phases: (1) baseline, (2) intervention, and (3) follow-up. In
each phase, the researcher takes repeated measurements of variables that indicate the
client's problems or needs at specified intervals over time. The researcher then observes
patterns of variation in the variables in each of the phases and between phases.
At baseline, there are measurements without an intervention, and analyses of those
observations can provide information to assist in the assessment of a client's problems.
The baseline phase provides a bench mark of where the client is without intervention; it
can indicate the extent and severity of problems as well as the degree to which they may
be spontaneously increasing or remitting to a nonproblem state. The intervention phase
provides information about the extent of changes in the frequency of the problem as the
social worker provides intervention for the client. During the intervention phase, the
clinical social worker observes the degree to which he or she implements the planned
intervention and whether the measurement patterns of the problem variables are similar to
or different from those at baseline. This observation allows the clinical social worker to
infer the effectiveness of intervention in relation to intervention goals and indicates
whether a problem is stabilizing, increasing, or decreasing. The social worker can
implement the intervention phase in most practice situations in which repeated
measurements over time are possible (see Chapter 4): after-care treatment, residential
treatment, psychotherapy in private practice, medical social work in hospital care
facilities, probation and parole supervision, marital counseling, group therapeutic
paradigms, and so forth. The social worker also can implement the intervention phase in
short-term treatment, but it is impractical in one-shot crisis interviews, such as
emergency intervention in natural disasters, traveler's aid, and so forth. In the
follow-up phase, the clinical social worker continues to record the problem variables but
terminates the intervention. This phase presumes that the clinical social worker has
ethically withdrawn the intervention because of the interventions both the client and
clinical social worker have agreed on or because the client has achieved therapeutic
goals. Obtaining follow-up information requires planning and the use of extra resources by
the social worker or the organization or agency in which the social worker is employed.
This model of baseline, intervention, and follow-up is consistent with the phase model of
direct practice, which incorporates a problem-solving approach, including assessment,
planning interventions, implementation, interventions, termination, and follow-up (Blythe
& Tripodi, 1989).
The model presented in this book, a basic A-B-A design (Barlow & Hersen, 1984), is
used because it is a logical extension of Cook and Campbell's (1979) interrupted
time-series design applied to single subjects, which may permit stronger inferences about
the effectiveness of an intervention than the A-B design. The A refers to a phase without
intervention, whereas B refers to intervention. Hence, the A-B-A design includes baseline,
intervention, and return to baseline (the follow-up phase). The A-B design does not have a
follow-up phase; hence, it does not permit analysis of what happens to the client after
termination or withdrawal of the intervention. Because the clinical social worker can
examine much information within the baseline, intervention, or follow-up phase for making
decisions within the phases in addition to comparisons among phases, this book refers to
those phases, rather than to the letters A and B.
This book intends to introduce readers to the A-B-A design model in detail; clinical
examples in subsequent chapters illustrate procedures for analysis. However, the following
example illustrates aspects of the model as well as potential problems in its application.
Example
Suppose a clinical social worker in private practice is working with Jim, a 15-year-old
male, who is depressed and who thinks critically of himself in relation to others each
day. Jim also has low self-esteem and does not engage in ordinary school activities with
his classmates. As part of the diagnostic or assessment process, which also includes
interviews with Jim's family and study of referral documents and protocols, the clinical
social worker, for example, concentrates on the problems of depression and self-critical
thoughts.
In discussions with Jim, the clinical social worker devises two variables: (1)
frequency of self-critical thoughts and (2) degree of depression. A self-critical thought
is one in which he thinks about how incompetent he is compared with others. The clinical
social worker asks Jim to tally the number of times he has self-critical thoughts each day
and to record those numbers for one week. Jim would count a second self-critical thought
only if other thoughts that are not self-critical intervene. The social worker also
devises a self-anchored rating scale of depression in consultation with Jim. The scale
ranges from 0 to 10; 0 = no depression, 2 = very little depression, 4 = some depression, 6
= moderate depression, 8 = very much depression, and 10 = extreme depression. The social
worker also asks Jim to rate his feelings of depression every day for one week. At the end
of one week -- the second session with the clinical social worker -- the social worker
constructs graphs to show baseline patterns of self-critical thoughts and severity of
depression (Figures 1 and 2).
Clearly, Jim perceives he is depressed. He indicates very much depression (8) or higher
every day of the week except Tuesday, which he rated 7. Furthermore, the same pattern
exists for the frequency of self-critical thoughts, which Jim rated 10 or higher every day
except Tuesday. Thus, there apparently is a strong association between the number of
self-critical thoughts and depression. However, it is unclear whether self-critical
thoughts come before or after the depression; Jim, though, indicated in an interview that
he tends to become depressed after he is self-critical. Within the social worker's overall
treatment plan, which includes discussions of incidents at home and at school as well as
Jim's relationships with peers and family, the social worker decides to use an
intervention designed to reduce Jim's self critical thoughts and, in turn, to possibly
reduce depression. The intervention is a cognitive intervention aimed at thought stopping
and includes reframing the context of self-critical decisions. The social worker instructs
Jim to change the comparisons from himself with others to only with himself whenever he
has a self-critical thought and to think of successful performances he has had at school
and in sports events. In addition, the social worker asks Jim to continue to record the
frequency of self-critical remarks and perceived depression. After two weeks of
intervention, the clinical social worker produces graphs to show the comparisons of
intervention with baseline (Figures 3 and 4).
Obviously, the frequency of self-critical thoughts (Figure 4) is reduced to 0 during
Friday, Saturday, and Sunday, the last three days of the two weeks of intervention.
However, the social worker notes that Jim's feelings of depression continue to exist
(Figure 3) and essentially are unchanged. The clinical social worker learns that there is
no simple relationship between depression and control of self-critical thoughts, contrary
to what Jim believes. This observation implies that assessment of factors that might lead
to depression should continue. Moreover, the social worker can reduce the cognitive
intervention directed toward Jim's self-critical thoughts in comparison with others.
If Jim no longer invokes the intervention, he and the social worker can determine, by
obtaining measurements of self-critical remarks on a daily basis during the follow up
period, whether there is a persistent change in the reduction of self-critical remarks.
As illustrated in the preceding example, single-subject design methodology is merely a
tool, but it can aid the social worker in making decisions pertinent to assessment and
practice effectiveness. When the clinical social worker uses the full single-subject
design model and adds other design variations (see Chapter 6), he or she can make
inferences that approximate causal relationships between the intervention and designated
outcomes or planned results. The emphasis in this book is on using the model and
variations of it as a framework for making clinical decisions. However, the clinical
social worker ultimately bases the decisions on his or her previous experiences, theory,
and knowledge of interventions and on other information derived from clinical observations
and interviews.
Levels of Knowledge
Single-subject designs produce or approximate three levels of knowledge: (1)
descriptive, (2) correlational, and (3) causal (Tripodi, 1983). Descriptive knowledge
consists of simple facts. For example, Jim's ratings of perceived depression for each day
of the week constitute descriptive knowledge about the severity of his depression.
Correlational knowledge is the description of a relationship between variables. In
comparing baseline to intervention on self-critical remarks for Jim, it is apparent that,
at baseline without intervention, there is a greater frequency of self-critical remarks,
but during the administration of the intervention, there is a reduction in the number of
self-critical remarks; hence, there is a correlation between the intervention and the
number of self-critical remarks. The relationship can be more aptly described as inverse
or negative: As intervention is introduced, the frequency of self-critical remarks is
reduced. If self-critical remarks increased as the intervention were introduced, the
relationship would be considered direct or positive. The highest level of knowledge is
causal, which includes correlational knowledge between an intervention and changes in a
problem variable as well as evidence that no variables other than the intervention are
responsible for the changes. Single-subject designs cannot achieve causal knowledge with
complete certainty; it can only be approximated. If the clinical social worker could
withdraw the intervention for Jim and if the intervention were a reversion to baseline
when Jim had a relatively high number of self-critical remarks, the clinical social worker
might obtain evidence for causality. This evidence would show that Jim would again
eliminate self-critical remarks when the cognitive intervention is introduced again. A
fourth level of knowledge is the development of hypotheses by conjecture, observation, or
interview. The social worker more likely will obtain this kind of knowledge through
qualitative research.
What evidence does the clinical social worker need to obtain different levels of
knowledge? The social worker can only have descriptive knowledge if there is evidence of
reliability (consistency) and validity (accuracy) for the variables the social worker is
measuring. These concepts are discussed in detail in Chapter 2. Correlational knowledge
exists when there are reliable and valid variables and when there is graphic or
statistical evidence of a relationship among the variables. Procedures to determine the
existence of correlational knowledge are discussed in Chapter 4. Causal knowledge about an
intervention depends on the following three criteria:
- The intervention precedes changes in problem variables, for example, the social worker
introduces the cognitive intervention for Jim before he makes reductions in self-critical
remarks.
- There is a correlation or association between the intervention and the variables that
indicate change. It is standard practice to conceive of the intervention as an independent
variable and the change variables as dependent variables.
- No other variables are responsible for observed changes in the dependent variables.
These other variables are internal validity threats (Cook & Campbell, 1979) (see
Chapter 4).
RELATIONSHIP BETWEEN CLINICAL PRACTICE AND SINGLE-SUBJECT DESIGN METHODOLOGY
Single-subject design methodology is insufficiently comprehensive to provide the basic
information for all practice decisions. Rather, single-subject design provides information
that clinical social workers can use to make key decisions in practice. Figure 5 shows the
relationship between information obtained from single-subject designs and decisions
clinical social workers make in practice. The baseline occurs during the assessment and
treatment formulation phase; intervention (treatment), during the treatment implementation
and monitoring phase; and follow-up, during the treatment evaluation phase. However, the
decisions designated for the practice phases do not include all of the decisions clinical
social workers make. Instead, they show that there is a direct relationship between
information obtained from single-subject design methodology and critical practice
decisions. For example, at baseline, the social worker can obtain information about the
measurement of a problem and its nature, severity, and persistence over time without
intervention.
The clinical social worker makes inferences in single-subject design methodology by
comparing measurements between phases (see Figures 3 and 4). For example, the social
worker compares measurements he or she made during intervention with measurements on the
same variable at baseline. If there are significant changes from problem severity to the
reduction or elimination of the problem, the social worker infers that there is a
relationship between the reduction of the problem and the introduction of treatment.
ARGUMENTS FOR THE USE OF SINGLE SUBJECT DESIGN METHODOLOGY
Bloom et al. (1993) have discussed a number of advantages to using single-subject
(single-system) designs, for example, social workers can use the designs to assess
problems and evaluate practice, and they can implement the designs in practice. However,
some of the arguments appear overstated and insufficiently geared to different levels and
types of practice situations. According to Bloom & Fischer (1982), single-subject
designs can do the following:
- They can be built into every practitioner's practice with each and every case/situation
without disruption of practice.
- They provide the tools for evaluating the effectiveness of our practice with each
client, group, or system with which we work.
- They focus on individual clients or systems. If there is any variation in effect from
one client or system to another, single system designs will be able to pick it up. (pp.
14-15)
Bloom et al. (1993) claimed that clinical social workers can use single-subject designs
in practice but not with every client. But this has not been the experience of those
clinical social workers who have used this methodology. One of the underlying themes in a
recent conference on clinical research was that social workers did not use the methodology
or could not apply it to all practice situations. (Videka-Sherman & Reid, 1990). An
approach offered by Gambrill and Barth (1980) is more moderate in perspective and
indicates the potential utility of single-subject designs with respect to the levels of
knowledge produced. Social workers can extend this approach by considering the levels of
knowledge the designs can generate within and between phases of the components baseline,
intervention, and follow-up (Table 1). For example, social workers can obtain descriptive
knowledge of the severity of the problem within each of the three phases. They can obtain
correlational knowledge of the intervention and problem severity by comparing observations
in the intervention phase with baseline or with follow-up observations. Clinical social
workers can infer causal knowledge, which is only approximate, based on information on all
components plus other information, such as interviewing, to help rule out alternative
explanations for positive changes associated with the intervention. Causal knowledge also
contains correlational and descriptive knowledge, and correlational knowledge also
includes descriptive knowledge (Tripodi, 1983). Hence, a major argument for the use of
single-subject designs is that they can provide different levels of knowledge that
practitioners can use to assist them in making decisions about assessment, treatment
implementation, and treatment evaluation (see Figure 5).
A second basic argument for the use of single-subject design methodology is that
clinical social workers can use the resultant information to inform themselves, clients
and their families, and the social workers' supervisors. Clinical social workers obtain
information to use in practice decision making. Furthermore, social workers can use the
information to show the client the extent to which he or she has progressed in relation to
agreed on goals in the social workerclient contract, for example, by referring to simple
graphs showing changes, positive or negative, over time. In addition, supervisors can
learn which problems social workers are focusing on and whether social workers have made
progress in reducing or maintaining the extent of those problems. Supervisors might then
use this information as a stimulus for discussing a particular client: Why is the
intervention working? Is it appropriate for this client? Is the information reliable? What
is the client's response when he or she sees a graph showing progress?
A third argument for the use of single-subject design methodology is that it produces
information for the profession. Clinical social workers can accumulate a log of similar
cases in which a particular intervention has or has not been effective. For example, a
social worker may use a method of providing health information and knowledge about
operations for close friends and relatives of a patient to reduce both the patient's and
their anxiety. The social worker may find that 18 of 20 people showed a reduction in
anxiety; hence, he or she justifiably retains that particular intervention in the clinical
repertoire. In this way, clinical social workers also can systematize their experiences in
using different interventions for their clients. Blythe and Briar (1985) have suggested
that practitioners can use single-subject designs to develop models of empirically based
practice, that is, prescriptions of what should be done and what is likely to be effective
in specific practice situations.
As Bloom and Fischer (1982) indicated, clinical social workers can use information from
single-subject designs to demonstrate accountability to clients and, if so employed, to
the agency in which they work. Clinical social workers also can use this information for
talks to community groups, for other presentations and conferences, and perhaps for
publication of clinical cases.
ARGUMENTS AGAINST THE USE OF SINGLE-SUBJECT DESIGN METHODOLOGY
Thomas (1978), who has used single-subject designs and has advocated for their use in
practice, argued that there are conflicts between practice and research in practice that
uses single-subject designs. He has discussed the use of single-subject designs to produce
causal knowledge by providing a number of experimental arrangements, the priority of which
is more important than the immediate practice situation. By definition, he has set up a
conflict between practice and research and then has proceeded to discuss their
differences. In contrast to Thomas's discussion, the view presented in this book is more
flexible in that the designs generate different levels of knowledge, following the ideas
of Gambrill and Barth (1980). Moreover, the perspective in this book is that practice
issues and decisions to help clients are the basic priorities; clinical social workers
will use single-subject design methodology if it follows natural occurrences of practice
and if the social workers can incorporate it as a tool within practice. For example,
social workers routinely use procedures such as manipulation of one variable at a time,
withholding of intervention, withdrawal of intervention before the client achieves
treatment goals, short intervention periods, and extended baseline observations in
experimentation to attempt to produce causal knowledge. However, social workers cannot
invoke many of the approaches to produce knowledge. This does not mean clinical social
workers cannot obtain useful knowledge; rather, they can obtain descriptive and
correlational knowledge and approximations to causal knowledge in many practice
situations.
Although single-subject design methodology does not fit all situations, this by no
means is an indictment of the methodology. Not even all practice methods fit all practice
situations. For example, medication and psychoeducational modalities might be applicable
to people with chronic schizophrenia, but not to college students with situational anxiety
during periods of examination. Differential diagnosis in practice is the basis on which
one may decide to use or not use a particular intervention. Analogously, clinical social
workers may more appropriately use different research methods, such as single-subject
designs. Grasso and Epstein (1992) have discussed different procedures for using a variety
of research methods other than single-subject design methodology.
However, a more difficult argument to overcome is one that affects many practice
situations and evaluations of practice: How can social workers study the effects of a
particular intervention when the client may be receiving other interventions from other
sources? In multidisciplinary settings -- for example, in a medical or psychiatric
hospital -- the client has contact with many professionals from which the client may
receive intervention. In a neuropsychiatric hospital, a patient may receive occupational
therapy, group counseling, individual counseling from a psychiatrist, or counseling from a
clinical social worker. Interventions may overlap, precluding study of one intervention.
Social workers can deal with this problem by assessing the degree to which the evaluation
methodology (for example, single-subject design methodology) is appropriate. (See Chapter
4 for a discussion on the procedures for discerning the context of interventions.) In
assessing the problem, the social worker may find that
- no other discernible intervention conflicts with the one he or she is evaluating; that
is, the intervention is unique and the social worker can evaluate it using single-subject
design methodology.
- the intervention and one or more other interventions overlap, so the social worker can
only evaluate the joint effects of the interventions.
- the intervention and other interventions overlap, and the nature of the intervention is
so ambiguous and diffuse that evaluation is unwarranted until the social worker can
specify the interventions more precisely.
Another argument against the use of single-subject design methodology is that it is too
mechanistic -- it does not present the whole view of the person. Although the social
worker uses systematic procedures, such as the repeated measurement of variables at
baseline, those measures do not represent the whole person. Measurements are indices of
the client's problems, selected for assessment and potential change through intervention.
Any specification of a phenomenon, whether in practice (by prioritizing and focusing on
specific features of a client in his or her situation) or in research (by systematically
obtaining repeated measurements over time for a particular problem variable), reduces the
phenomenon to a segment of its totality. However, the clinical social worker may still
view the total situation of the client in his or her environment. The social worker can
interpret in that context the specific findings of problem changes selected for work by
the clinical social worker and the client.
Many clinicians have argued, though, that it is difficult, and perhaps impossible, to
obtain baseline measurements. The social worker may approximate baseline measurements
through retrospection or by using available data from other sources when there is
insufficient time to obtain measurements before intervention (see Chapter 3). However, the
proponents of this argument implicitly are looking at the use of single-subject design
methodology to produce casual knowledge. The social worker can obtain descriptive
knowledge by studying the trends in measurements within the follow-up phase. Moreover, he
or she can derive correlational knowledge from the comparisons of measurements during the
intervention and follow-up phases. For example, the clinical social worker may initiate an
intervention immediately with a substance-abusing client. During intervention, the client
reduces the substance abuse, and the clinical social worker and client believe the client
has achieved the treatment goal. The social worker also takes measurements at follow-up to
detect the possibility of relapse (a return to a condition of severe substance abuse). If,
on the withdrawal of intervention, there is a relapse, the clinical social worker can
infer that there is a correlation between treatment and the severity of substance abuse.
(See Chapters 2, 3, and 4 for procedures for determining correlational relationships.)
ORGANIZATION OF THE BOOK
Chapter 2, on measurement is basic to the other chapters. It presents the process of
measurement and criteria for selecting simple, but useful measures. It describes problems
that are typical for clients in mental health, industry, and other clinical settings and
discusses the measurement of problems such as absenteeism, depression, anxiety,
productivity, and stress.
Chapter 3 defines baselines, the first phase of the single-subject design model, and
explicates their purposes for assessment and evaluation. Furthermore, the chapter presents
arguments for and against the use of baselines. It details the process of constructing
baselines, including the plotting and analysis of graphic patterns, statistical analysis,
and the illustration of practice decisions. Moreover, it discusses procedures for
simultaneous baselining of clients, situations, and problem variables.
Intervention, the second phase of the basic model, is discussed and defined in Chapter
4. The author provides methods for specifying interventions and discusses arguments for
and against the use of measurement during this phase. In addition, the chapter illustrates
comparisons of patterns of measurement at the intervention phase to the baseline phase and
considers different patterns of change or no change with respect to clinical social
workers' decisions.
Follow-up, the third phase of the model, is discussed and described in Chapter 5, which
presents arguments for and against the use of measurements in this phase. The chapter
illustrates the process of measurement during follow-up, shows how to derive patterns that
are obtained by comparing follow-up to intervention and to baseline, and discusses those
patterns with respect to practice decisions.
Chapter 6 presents three variations of the basic model: (1) multiple baseline design
with clients, situations, or problems; (2) graduated intensity designs; and (3) natural
withdrawalreversal designs. The author presents arguments for and against the use of
these designs and discusses inferences that the social worker can make about the
effectiveness of interventions.
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