Social workers often use elements of single case designs in their work with clients, although they may not realize it. Our practice requires us to observe the effect of our interventions on clients and the achievement of their goals. If it does, we have identified an effective intervention for them, but if it is not effective, we try something else. By performing these observations systematically, we are conducting some aspects of single subject research.
In a clinical practice setting, the effectiveness of interventions can most readily be evaluated by SCDs [single-subject research, also termed single-case designs]. Additionally, given the fact that social workers are the largest providers of mental health services in the United States, it is not surprising that, more and more, SCDs are being used in the delivery of mental health services. (Georgoulakis, Zollmann, Pate, & Hallet, 2017).
While there are many research articles on the use of single-case designs in education, there are few in social work, which is surprising since most of us work one-to-one with clients, and we rarely have the opportunity to use group experimental procedures where clients are randomly assigned to conditions.
The social work interventions in single-system research require knowledge of the clients, the target problem or condition, and evidence-based practices, if any are available, and should address the research question. For example, what activities could comprise case management in the social worker’s intervention with George in the assigned case? Some examples might include a weekly session with the client or phone contact three times per week, home visits, making referrals for the client, and advocacy.
An evidence-based intervention developed from a single subject research design requires careful planning, implementation, and analysis. The greatest obstacles to single-system research in social work are urgency of client needs, time, and funding since single-system must conform to highly rigorous procedures to meet standards of scientific quality and validity.
Citing Jomer, Carr, Halle, McGee, Odom, and Wolery (2005), Tankersley, Cook, and Cook (2008) caution that single subject research must meet or exceed the same standards of scientific rigor in the same domains that are applied to experimental studies with groups. As in experimental studies, single case designs must include a thorough “description of participants and settings, the dependent variable, the independent variable, baseline [measures of the frequency or magnitude of the problem with careful attention paid to] experimental control/internal validity, external validity, and social validity” (p. 525).
In addition to scientific rigor for research validity, Tankersley, Cook, and Cook (2008) propose additional standards to ensure that the conclusions of single-case research are evidence based:
“(a) at least five studies that meet minimally acceptable methodological criteria, document experimental control, and have been published in peer-reviewed journals;
(b) the studies must be conducted by at least three different researchers across at least three different geographical locations; and
(c) the studies cumulatively include a total of at least 20 participants.” (p. 525).
To determine if a study is a single-system research design, consider these questions:
observations of the target behavior or condition
self-report from the client (most common when monitoring thoughts or feelings)
goal attainment scales (how much a desirable behavior or situation is increasing) and
target problem scales (measuring how much an undesirable situation is decreasing).
Clinical scales, goal-attainment scales, and target scales are commonly used to assess progress.
Clinical scales are used to evaluate the presence and severity of psychiatric symptoms including depression, anxiety, ADHD, and dementia.
Goal attainment scales are typically used to assess performance – how well or how often a behavior is performed, or if the person achieves a standard for success (yes/no)
Target problem scales (also called target scales) are used when a goal is broken into intermediate steps (targets). The client’s level of success in achieving each target step toward the goal is monitored.
What ethical measures have been taken? Usually, ethical measures involve informed consent and oversight from the social worker’s organization.
Do the interventions conform to the core values of the Code of Ethics of the National Association of Social Workers (i.e., service, social justice, dignity and worth of the person, importance of human relationships, integrity, and competence)?
What types of single-system (case) research design are used in social work?
At least four different single subject designs are common in social work. They usually fall into one of the following categories:
1a. Concurrent AB is a design in which several target behaviors are observed before an intervention and then the interventions are applied to the all the problems simultaneously. It is often used when multiple problems are urgent and no time is available to see how an intervention impacts one problem before applying an intervention to another problem. Since the interventions are applied without time allowed between the them to determine how each one responds to the treatment, concurrent AB design has poor external validity.
Concurrent AB Design
Concurrent AB Design
The concurrent AB design does not allow for generalizations (external validity) because we do not know what is influencing the changes in the second and third behaviors due to carryover effects.
For example, a client struggling with a mental health issue who does well with medication may decide that he no longer needs the medication, only to observe that the symptoms of his mental illness are returning when the medication is discontinued. If he finds the symptoms remitting a second time when he resumes the medication, he has imposed an ABAB single case design on his own problem without realizing it. These results enable the social worker and the client to conclude that the medications make an important difference in his well-being.
In this design, baseline data are collected on two or more behaviors at the same time with the expectation that the target behaviors or conditions will respond to the selected intervention (in George’s case, the task-centered solution focused method of case management). This design is applied in steps with each behavior being addressed in order.
The process requires baseline information to be obtained on each target behavior or condition. Then the intervention is applied to one target problem while the conditions for other target problems remain at baseline and are not treated. Cooper, Heron, & Heward note that “interventions cannot be applied to the next behavior until the previous behavior change [if any] has been established” (2007, p. 214). After changes to the first target problem are stable, the intervention can be applied to subsequent target problems in sequence, holding untreated problems at baseline while the intervention is applied to the second behavior and the first behavior simultaneously. When the responses of the second behavior to the intervention are stable, the intervention is applied to the third behavior, which has been held at baseline while the other behaviors were treated. In this manner, the researcher can observe how each problem responds to the intervention.
How is the multiple baseline research design different from the ABC design? In the multiple baseline design, the intervention continues to be applied to the first target when the intervention is applied to the second target. In the ABC design, there is one target behavior and two interventions. The behavior baseline is A; which is measured when intervention #1 is applied (B); then intervention #1 is replaced with intervention #2 (C). The problem with this method is that there could be carryover effects from Intervention #1 that occur when Intervention #2 is applied, making Intervention #2 appear more effective than it actually is, because the behavior is responding to the earlier intervention.
How is the multiple-baseline-over-behaviors design different from concurrent AB? The concurrent AB design does not allow time for the intervention to be applied in sequence to a set of target behaviors. The intervention is applied to all the behaviors at once after a short baseline period. As a result, it is not possible to estimate how the intervention affects each target behavior differently since there may be carryover effects from changes in a target behavior.
For example, consider a high school student who cannot stay awake in their first period algebra class. Let’s assume that the social worker decides to offer a reward system for getting up on time, eating breakfast, and paying attention in their first period algebra class. The reward system is the intervention.
The social worker applies the reward system to all the behaviors at once. In two weeks, they find that there is an improvement in the student’s ability to pay attention in the algebra class. Is it because of the reward system or because the student now has eaten breakfast and is waking up on time? There is no way to know how much of an effect the intervention has on this behavior because the true cause of the change is not clear.
In a multiple-baseline-over-behaviors design, the intervention is applied to each behavior one at a time to evaluate the effect of the intervention separately on each target behavior.
Multiple baseline designs can address different target problems in the same individual (most common use in social work) and are also used to address the same problems by other clients served individually or the same problems in two or more different settings.
Multiple baseline across behaviors design
Multiple baseline across behaviors design
In our example, the multiple baseline design helps to determine if an intervention is effective with several different target problems while the design controls for the effect of external events on the target behaviors or conditions.
Your task for this discussion
The case study of George, assigned for this week in Social Work Case Studies: Concentration Year, includes information regarding the client that can be used by the social worker to make informed choices. This information in addition to the social worker’s education on the issues is called subject matter expertise. To be meaningful, research must include the knowledge the social worker has gained from other studies and from experiences with similar clients and knowledge of research design. Subject matter expertise is essential for meaningful, relevant research.
(important ) To prepare for this Discussion, read the case study of George (Social Work Research: Single Subject) and the criteria for using single-system (subject) designs in this week’s learning resources and in the list provided above.
Imagine that you are the social worker assigned to a research project to assist your client, George. After reading the case in the Sessions book, you have some knowledge of his situation. Note these essential elements of the case:
6.. You are an experienced and competent social worker.
Keep in mind that single case/system/subject designs are applied when the researcher wants to discover the impact of intervention(s) on one person who serves as their own control.
Then answer the following questions:
1.Does the approach used by the social worker with George meet the criteria for a single case design? Explain your reasoning (1-2 sentences).
In evaluating the social worker’s use of an intervention consisting of case management and solution focused and task-centered methods, I observed (select one: significant improvement, moderate improvement, slight improvement, no improvement, worsening problems) in George’s home safety behavior.
I also observed (select one: significant improvements, moderate improvements, slight improvements, no improvements, worsening problems) in his personal care behavior and (select one: significant improvements, moderate improvements, slight improvements, no improvements, worsening problems) in his mobility.
(Copy this sentence and add answer, following this format: These results suggest that the selected intervention was (select one: effective, promising (evidence of effectiveness is present but small), or ineffective) for ensuring home safety, (select one: effective, promising (evidence of effectiveness is present but small), or ineffective) for improving personal care, and (select one: effective, promising (evidence of effectiveness is present but small), or ineffective) for increasing mobility.
Given the importance of addressing these issues in my community and the scarcity of funding at this time, I (would/would not) support a program to implementing the task-centered solution focused case management intervention for __ (home safety, personal care, mobility – choose all, some, one, or none).