In a single-subject study demonstrating that a specific treatment successfully reduced self-injurious behavior in two children with intellectual disabilities, the main external validity concern is whether the treatment effect can be generalized to other children with intellectual disabilities who were not included in the study.

A single-subject study demonstrates that a specific behavioral intervention successfully reduces self-injurious behavior in two children with intellectual disabilities. Which of the following best explains why this finding raises a concern regarding external validity?

In a single-subject study, a researcher finds that a 'weighted vest' reduces hyperactivity in two boys with ADHD. Match each research observation or action to its corresponding implication for validity.

A researcher conducts a single-subject study where a specific treatment successfully reduces self-injury in two children with intellectual disabilities. Arrange the following steps to reflect a logical analysis of the study's validity, moving from the initial evidence to the identification of external validity concerns.

In the research example involving a treatment that reduces self-injury in $2$ children, what is the primary challenge that represents a concern for external validity?

True or False: Demonstrating that a behavioral intervention reduces self-injury in $2$ children with intellectual disabilities is sufficient to resolve the concern that the findings may not apply to other children with similar disabilities.

A researcher claims that a behavioral treatment for self-injury is 'proven effective' for all children with intellectual disabilities based on success with only $2$ participants. To critically evaluate the scientific merit of this broad conclusion, one must recognize that the study's primary limitation is its lack of _____, which prevents the findings from being reliably generalized to the broader population.

A researcher conducts a single-subject study showing that a behavioral treatment reduces self-injury in two children with intellectual disabilities. Match each element of this study to the external validity concept it best illustrates.

When analyzing why a single-subject study demonstrating that a behavioral treatment reduced self-injury in two children with intellectual disabilities cannot be used to conclude that the treatment will work for all children with intellectual delays, a researcher identifies that the main limiting factor is the _____ of participants in the original study.

A school psychologist must decide whether to recommend a self-injury treatment — shown effective in a single-subject study with two children with intellectual disabilities — to a district serving many children with intellectual delays. Arrange the following evaluative steps in the most logical order for arriving at a justified recommendation.

Describe the textbook example illustrating external validity concerns in single-subject research. In your description, identify the targeted behavior, the number of participants studied, the treatment's outcome for those participants, and the primary question or challenge regarding generalizability that researchers face based on this outcome.

Evaluate the psychologist's recommendation. Explain the challenge of external validity in this scenario and explain why a strong treatment effect in this study does not automatically justify district-wide implementation for all children with intellectual delays.

A clinical psychologist wants to apply the behavioral treatment from the self-injury study (which successfully helped $2$ children with intellectual disabilities) to a new patient with similar intellectual delays. Based on the external validity limitations of single-subject designs, what must the psychologist do to determine if the treatment is actually effective for this new patient?