44 Overview of Single-Subject Research
Learning Objectives
- Explain what single-subject research is, including how it differs from other types of psychological research.
- Explain who uses single-subject research and why.
What Is Single-Subject Research?
Single-subject research is a type of quantitative research that involves studying in detail the behavior of each of a small number of participants. Note that the term single-subject does not mean that only one participant is studied; it is more typical for there to be somewhere between two and 10 participants. (This is why single-subject research designs are sometimes called small-n designs, where n is the statistical symbol for the sample size.) Single-subject research can be contrasted with group research, which typically involves studying large numbers of participants and examining their behavior primarily in terms of group means, standard deviations, and so on. The majority of this textbook is devoted to understanding group research, which is the most common approach in psychology. But single-subject research is an important alternative, and it is the primary approach in some more applied areas of psychology.
Before continuing, it is important to distinguish single-subject research from case studies and other more qualitative approaches that involve studying in detail a small number of participants. As described in Chapter 6, case studies involve an in-depth analysis and description of an individual, which is typically primarily qualitative in nature. More broadly speaking, qualitative research focuses on understanding people’s subjective experience by observing behavior and collecting relatively unstructured data (e.g., detailed interviews) and analyzing those data using narrative rather than quantitative techniques. Single-subject research, in contrast, focuses on understanding objective behavior through experimental manipulation and control, collecting highly structured data, and analyzing those data quantitatively.
Assumptions of Single-Subject Research
Again, single-subject research involves studying a small number of participants and focusing intensively on the behavior of each one. But why take this approach instead of the group approach? There are several important assumptions underlying single-subject research, and it will help to consider them now.
First and foremost is the assumption that it is important to focus intensively on the behavior of individual participants. One reason for this is that group research can hide individual differences and generate results that do not represent the behavior of any individual. For example, a treatment that has a positive effect for half the people exposed to it but a negative effect for the other half would, on average, appear to have no effect at all. Single-subject research, however, would likely reveal these individual differences. A second reason to focus intensively on individuals is that sometimes it is the behavior of a particular individual that is primarily of interest. A school psychologist, for example, might be interested in changing the behavior of a particular disruptive student. Although previous published research (both single-subject and group research) is likely to provide some guidance on how to do this, conducting a study on this student would be more direct and probably more effective.
A second assumption of single-subject research is that it is important to discover causal relationships through the manipulation of an independent variable, the careful measurement of a dependent variable, and the control of extraneous variables. For this reason, single-subject research is often considered a type of experimental research with good internal validity. Recall, for example, that Hall and his colleagues measured their dependent variable (studying) many times—first under a no-treatment control condition, then under a treatment condition (positive teacher attention), and then again under the control condition. Because there was a clear increase in studying when the treatment was introduced, a decrease when it was removed, and an increase when it was reintroduced, there is little doubt that the treatment was the cause of the improvement.
A third assumption of single-subject research is that it is important to study strong and consistent effects that have biological or social importance. Applied researchers, in particular, are interested in treatments that have substantial effects on important behaviors and that can be implemented reliably in the real-world contexts in which they occur. This is sometimes referred to as social validity (Wolf, 1976)[1]. The study by Hall and his colleagues, for example, had good social validity because it showed strong and consistent effects of positive teacher attention on a behavior that is of obvious importance to teachers, parents, and students. Furthermore, the teachers found the treatment easy to implement, even in their often-chaotic elementary school classrooms.
Who Uses Single-Subject Research?
Single-subject research has been around as long as the field of psychology itself. In the late 1800s, one of psychology’s founders, Wilhelm Wundt, studied sensation and consciousness by focusing intensively on each of a small number of research participants. Herman Ebbinghaus’s research on memory and Ivan Pavlov’s research on classical conditioning are other early examples, both of which are still described in almost every introductory psychology textbook.
In the middle of the 20th century, B. F. Skinner clarified many of the assumptions underlying single-subject research and refined many of its techniques (Skinner, 1938)[2]. He and other researchers then used it to describe how rewards, punishments, and other external factors affect behavior over time. This work was carried out primarily using nonhuman subjects—mostly rats and pigeons. This approach, which Skinner called the experimental analysis of behavior—remains an important subfield of psychology and continues to rely almost exclusively on single-subject research. For excellent examples of this work, look at any issue of the Journal of the Experimental Analysis of Behavior. By the 1960s, many researchers were interested in using this approach to conduct applied research primarily with humans—a subfield now called applied behavior analysis (Baer, Wolf, & Risley, 1968)[3]. Applied behavior analysis plays an especially important role in contemporary research on developmental disabilities, education, organizational behavior, and health, among many other areas. Excellent examples of this work (including the study by Hall and his colleagues) can be found in the Journal of Applied Behavior Analysis.
Although most contemporary single-subject research is conducted from the behavioral perspective, it can in principle be used to address questions framed in terms of any theoretical perspective. For example, a studying technique based on cognitive principles of learning and memory could be evaluated by testing it on individual high school students using the single-subject approach. The single-subject approach can also be used by clinicians who take any theoretical perspective—behavioral, cognitive, psychodynamic, or humanistic—to study processes of therapeutic change with individual clients and to document their clients’ improvement (Kazdin, 1982)[4].
- Wolf, M. (1976). Social validity: The case for subjective measurement or how applied behavior analysis is finding its heart. Journal of Applied Behavior Analysis, 11, 203–214. ↵
- Skinner, B. F. (1938). The behavior of organisms: An experimental analysis. New York, NY: Appleton-Century-Crofts. ↵
- Baer, D. M., Wolf, M. M., & Risley, T. R. (1968). Some current dimensions of applied behavior analysis. Journal of Applied Behavior Analysis, 1, 91–97. ↵
- Kazdin, A. E. (1982). Single-case research designs: Methods for clinical and applied settings. New York, NY: Oxford University Press. ↵
How do social workers know the right thing to do? It's an important question. Incorrect social work actions may actively harm clients and communities. Timely and effective social work interventions further social justice and promote individual change. To make the right choices, we must have a basis of knowledge, the skills to understand it, and the commitment to growing that knowledge. The source of social work knowledge is social science. This book is about how to understand and apply it to social work practice.
Chapter outline
- 1.1 How do we know what we know?
- 1.2 Science, social science, and social work
- 1.3 Why should we care?
- 1.4 Understanding research
Content advisory
This chapter discusses or mentions the following topics: stereotypes of people on welfare, sexual harassment and sexist job discrimination, sexism, poverty, homelessness, mental illness, and substance abuse.
How do social workers know the right thing to do? It's an important question. Incorrect social work actions may actively harm clients and communities. Timely and effective social work interventions further social justice and promote individual change. To make the right choices, we must have a basis of knowledge, the skills to understand it, and the commitment to growing that knowledge. The source of social work knowledge is social science. This book is about how to understand and apply it to social work practice.
Chapter outline
- 1.1 How do we know what we know?
- 1.2 Science, social science, and social work
- 1.3 Why should we care?
- 1.4 Understanding research
Content advisory
This chapter discusses or mentions the following topics: stereotypes of people on welfare, sexual harassment and sexist job discrimination, sexism, poverty, homelessness, mental illness, and substance abuse.
Learning Objectives
- Find a topic to investigate
- Create a working question
Choosing a social work research topic
According to the Action Network for Social Work Education and Research (ANSWER), social work research is conducted to benefit “consumers, practitioners, policymakers, educators, and the general public through the examination of societal issues” (ANSWER, n.d., para. 2). [1] Common social issues that are studied include “health care, substance abuse, community violence, family issues, child welfare, aging, well-being and resiliency, and the strengths and needs of underserved populations” (ANSWER, n.d., para. 2). This list is certainly not exhaustive. Social workers may study any area that impacts their practice. However, the unifying feature of social work research is its focus on promoting the well-being of target populations.
If you are an undergraduate social work student that is not yet practicing social work, then how do you identify a researchable topic? Part of the joy in being a social work student is figuring out what areas of social work are appealing to you. Perhaps there are certain theories that speak to you, based on your values or experiences. Perhaps there are social issues you wish to change. Perhaps there are certain groups of people you want to help. Perhaps there are clinical interventions that interest you. Any one of these areas is a good place to start. At the beginning of a research project, your focus should be finding a social work topic that is interesting enough to spend a semester reading and writing about.
A good topic selection plan begins with a general orientation into the subject you are interested in pursuing in more depth. Here are some suggestions when choosing a topic area:
- Pick an area of interest or experience, or an area where you know there is a need for more research.
- It may be easier to start with “what” and “why” questions and expand on those. For example, what are the best methods of treating severe depression? Or why are people receiving SNAP more likely to be obese?
- If you already have practice experience in social work through employment, an internship, or volunteer work, think about practice issues you noticed in the placement.
- Ask a professor, preferably one active in research, about possible topics.
- Read departmental information on research interests of the faculty. Faculty research interests vary widely, and it might surprise you what they’ve published on in the past. Most departmental websites post the curriculum vitae, or CV, of faculty which lists their publications, credentials, and interests.
- Read a research paper that interests you. The paper’s literature review or background section will provide insight into the research question the author was seeking to address with their study. Is the research incomplete, imprecise, biased, or inconsistent? As you’re reading the paper, look for what’s missing. These may be “gaps in the literature” that you might explore in your own study. The conclusion or discussion section at the end may also offer some questions for future exploration. A recent blog posting in Science (Pain, 2016) [2] provides several tips from researchers and graduate students on how to effectively read these papers.
- Think about papers you enjoyed researching and writing in other classes. Research is a unique class and will use the tools of social science for you to think more in depth about a topic. It will bring a new perspective that will deepen your knowledge of the topic.
- Identify and browse journals related to your research interests. Faculty and librarians can help you identify relevant journals in your field and specific areas of interest.
How do you feel about your topic?
Perhaps you have started with a specific population in mind, such as youth who identify as LGBTQ or visitors of a local health clinic. Perhaps you choose to start with a specific social problem, such as gang violence, or social policy or program, such as zero-tolerance policies in schools. Alternately, maybe there are interventions that you are interested in learning more about, such as dialectical behavioral therapy or applied behavior analysis. Your motivation for choosing a topic does not have to be objective. Because social work is a values-based profession, social work researchers often find themselves motivated to conduct research that furthers social justice or fights oppression. Just because you think a policy is wrong or a group is being marginalized, for example, does not mean that your research will be biased. Instead, it means that you must understand how you feel, why you feel that way, and what would cause you to feel differently about your topic.
Start by asking yourself how you feel about your topic. Be totally honest, and ask yourself whether you believe your perspective is the only valid one. Perhaps yours isn’t the only perspective, but do you believe it is the wisest one? The most practical one? How do you feel about other perspectives on this topic? If you are concerned that you may design a project to only achieve answers that you like and/or cover up findings that you do not like, then you must choose a different topic. For example, a researcher may want to find out whether there is a relationship between intelligence and political affiliation, while holding the personal bias that members of her political party are the most intelligent. Her strong opinion would not be a problem by itself, however if she feels rage when considering the possibility that the opposing party’s members are more intelligent than those of her party, then the topic is probably too conflicting to use for unbiased research.
It is important to note that strong feelings about a topic are not always problematic. In fact, some of the best topics to research are those that are important to us. What better way to stay motivated than to study something that you care about? You must be able to accept that people will have a different perspective than you do, and try to represent their viewpoints fairly in your research. If you feel prepared to accept all findings, even those that may be unflattering to or distinct from your personal perspective, then perhaps you should intentionally study a topic about which you have strong feelings.
Kathleen Blee (2002) [3] has taken this route in her research. Blee studies hate movement participants, people whose racist ideologies she studies but does not share. You can read her accounts of this research in two of her most well-known publications, Inside Organized Racism and Women of the Klan. Blee’s research is successful because she was willing to report her findings and observations honestly, even those about which she may have strong feelings. Unlike Blee, if you conclude that you cannot accept or share with findings that you disagree with, then you should study a different topic. Knowing your own hot-button issues is an important part of self-knowledge and reflection in social work.
Social workers often use personal experience as a starting point for what topics are interesting to cover. As we’ve discussed here, personal experience can be a powerful motivator to study a topic in detail. However, social work researchers should be mindful of their own mental health during the research process. A social worker who has experienced a mental health crisis or traumatic event should approach researching related topics with caution. There is no need to retraumatize yourself or jeopardize your mental health for a research paper. For example, a student who has just experienced domestic violence may want to know about Eye Movement Desensitization and Reprocessing (EMDR) therapy. While the student might gain some knowledge about potential treatments for domestic violence, they will likely have to read through many stories and reports about domestic violence. Unless the student’s trauma has been processed in therapy, conducting a research project on this topic may negatively impact the student’s mental health. Nevertheless, she will acquire skills in research methods that will help her understand the EMDR literature and whether to begin treatment in that modality.
Whether you feel strongly about your topic or not, you will also want to consider what you already known about it. There are many ways we know what we know. Perhaps your mother told you something is so. Perhaps it came to you in a dream. Perhaps you took a class last semester and learned something about your topic there, or you may have read something about your topic in your local newspaper or in People magazine. We discussed the strengths and weaknesses associated with some of these different sources of knowledge in Chapter 1, and we’ll talk about other sources of knowledge, such as prior research in the next few sections. For now, take some time to think about what you know about your topic from all possible sources. Thinking about what you already know will help you identify any biases you may have, and it will help as you begin to frame a question about your topic.
What do you want to know?
Once you have a topic, begin to think about it in terms of a question. What do you really want to know about the topic? As a warm-up exercise, try dropping a possible topic idea into one of the blank spaces below. The questions may help bring your subject into sharper focus and provide you with the first important steps towards developing your topic.
- What does ___ mean? (Definition)
- What are the various features of ___? (Description)
- What are the component parts of ___? (Simple analysis)
- How is ___ made or done? (Process analysis)
- How should ___ be made or done? (Directional analysis)
- What is the essential function of ___? (Functional analysis)
- What are the causes of ___? (Causal analysis)
- What are the consequences of ___? (Causal analysis)
- What are the types of ___? (Classification)
- How is ___ like or unlike ___? (Comparison)
- What is the present status of ___? (Comparison)
- What is the significance of ___? (Interpretation)
- What are the facts about ___? (Reportage)
- How did ___ happen? (Narration)
- What kind of person is ___? (Characterization/Profile)
- What is the value of ___? (Evaluation)
- What are the essential major points or features of ___? (Summary)
- What case can be made for or against ___? (Persuasion)
- What is the relationship between _____ and the outcome of ____? (Exploratory)
Take a minute right now and write down a question you want to answer. Even if it doesn’t seem perfect, everyone needs a place to start. Make sure your research topic is relevant to social work. You’d be surprised how much of the world that encompasses. It’s not just research on mental health treatment or child welfare services. Social workers can study things like the pollution of irrigation systems and entrepreneurship in women, among infinite other topics. The only requirement is your research must inform action to fight social problems faced by target populations.
Your question is only a starting place, as research is an iterative process, one that is subject to constant revision. As we progress in this textbook, you’ll learn how to refine your question and include the necessary components for proper qualitative and quantitative research questions. Your question will also likely change as you engage with the literature on your topic. You will learn new and important concepts that may shift your focus or clarify your original ideas. Trust that a strong question will emerge from this process.
Key Takeaways
- Many researchers choose topics by considering their own personal experiences, knowledge, and interests.
- Researchers should be aware of and forthcoming about any strong feelings they might have about their research topics.
- There are benefits and drawbacks associated with studying a topic about which you already have some prior knowledge or experience. Researchers should be aware of and consider both.
- Writing a question down will help guide your inquiry.
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