Research Goals and Methods
Psychological research has four broad goals: (1) description, (2) prediction, (3) explanation, and (4) replication. Psychologists use different methods to accomplish each goal. For example, a psychologist who wants to describe the essential characteristics of ADHD might use a case study or survey, whereas a psychologist interested in explaining how stimulant medication reduces children’s ADHD symptoms would likely conduct an experiment. In this section, we will examine some of the most common research methods used in the field of abnormal child psychology.
How Do Psychologists Describe Behavior?
Case Studies
A case study is a detailed description of a person, group, or phenomenon. Researchers who conduct case studies provide as much detail as possible about the person’s background, current functioning, and other relevant aspects of his or her life. Case studies may also describe the person’s development or response to treatment. Case studies focus on idiographic assessment—that is, they assess a person’s unique abilities, experiences, and behaviors (Fishman, 2018b).
Case studies are especially useful to describe new disorders. For example, in 1932, two German doctors named Franz Kramer and Hans Pollnow described children with a new condition that they called “hyperkinetic disease” (Lange, Reichl, Lange, Tucha, & Tucha, 2010). The children had no history of injury or illness, yet their behavior caused problems at home and school. Their most striking feature was their hyperactivity:
These children cannot sit still for a second. They run up and down the room, climb about preferring high furniture in particular, and are displeased when deterred from acting out their motor impulses. They indiscriminately touch or move everything available without pursuing a goal.
From Science to Practice: A Cure for Headaches
In 1937, a young pediatrician named Charles Bradley was treating a boy with chronic headaches (Strohl, 2011). When traditional treatments failed, Bradley tried to alleviate the boy’s headaches using a new stimulant medication called Benzedrine. Although Benzedrine had little effect on the boy’s headaches, it caused an immediate and dramatic increase in the boy’s attention and academic performance. Bradley decided to test the medication with other children and described their response:
The most spectacular change in behavior brought about by the use of Benzedrine was the remarkably improved school performance of about half the children. They were more interested in their work and performed it more quickly and accurately. In addition, they showed a decrease in motor activity and became emotionally subdued without losing interest in their surroundings.
Image courtesy of the National Library of Medicine
Bradley had stumbled upon the use of stimulants as an effective way to treat ADHD. Today, medications like amphetamine (Adderall) and methylphenidate (Ritalin) are the most effective treatments for this disorder (Faraone & Buitelaar, 2010).
Many of the boys also showed problems with attention and concentration:
The children cannot concentrate on difficult tasks. They also show no perseverance in their activities. They often disturb class, have difficulty playing harmoniously with others, and are generally unpopular with peers.
Kramer and Pollnow’s descriptions provide the basis for the disorder we now call ADHD. The two broad clusters of symptoms that they identified, hyperactivity and inattention, are still used today to diagnose children with this disorder. Another clinician, Charles Bradley, used the case study approach to describe a possible treatment for these children as described in the From Science to Practice section.
Case studies have several limitations. Most importantly, the results of a case study may not generalize to a wider population. Although stimulant medication worked for several of Bradley’s patients, it wasn’t until the 1950s that Ritalin was shown to help most children with attention problems. Case studies are also prone to the biases of the researcher who conducts them. Bradley may have observed improvements in his patients simply because he expected the medication to help them. Finally, because each child is unique, the results of case studies are difficult to replicate. We need to conduct systematic studies, with larger samples of children, before we can be sure that the phenomena described in case studies are accurate and applicable to a wide range of children.
Surveys
Surveys are often used to describe large groups of children. Whereas case studies focus on the idiographic assessment of an individual child, surveys focus on nomothetic assessment—that is, information about how groups of children typically think, feel, or act. For example, psychologists might conduct surveys to determine the percentage of school-age children with ADHD, the age at which children first develop symptoms, or parents’ attitudes toward medication to treat the disorder.
The results of a survey depend on how participants are selected. Researchers cannot survey everyone in the entire population. Instead, researchers must select a sample of participants for their study. Ideally, researchers will use random selection, that is, they will select participants so that each person in a given population has an equal chance of being included in the study. If participants are randomly selected, then the information they provide should reflect the characteristics of the general population (Hsu, 2017).
For example, researchers at the Centers for Disease Control wanted to determine the prevalence of ADHD among children in the United States. They randomly selected a large sample of children using records from the federal census. Then, they asked the parents of each randomly selected child to report if their child had ever been diagnosed with ADHD. The researchers found that 9.1% of children had been diagnosed with ADHD, reflecting about 6.1 million children across the country. Because the researchers randomly selected participants for the survey, they can be reasonably confident that the data they gathered reflect the prevalence of ADHD in the general population (Danielson et al., 2018).
Most surveys are quantitative, that is, they collect numerical data or ratings provided by children, parents, or other informants. For example, a researcher might ask a parent if her child has ever been diagnosed with ADHD or ask a teacher to report the severity of his student’s attention problems on a scale ranging from 1 (low) to 7 (high). Surveys can also be qualitative, that is, they may ask respondents to provide verbal descriptions of children’s behavior. For example, survey questions might ask a parent to list three strengths about her child or ask a teacher to describe the child’s typical behavior during class.
Neuroimaging
Neuroimaging methods are also used to describe the brain structure and functioning of children with mental health problems. Beginning in the 1970s, clinicians and researchers used computed tomography (CT) to obtain more detailed images of the brain. In CT scanning, multiple images are taken using a movable X-ray device. A computer integrates these images to provide a clear picture of the brain. Unfortunately, CT scanning exposes patients to radiation. Consequently, it must be used sparingly with children (Roberts, 2020).
In the 1980s, a new tool was developed: magnetic resonance imaging (MRI). MRI technology is based on the fact that when body tissues are placed in a strong magnetic field and exposed to a brief pulse of radiofrequency energy, cells from the tissue emit a brief signal, called a resonance.
