Which statement best describes the generalizability issue raised by college sophomore samples?

• A. General integrity of findings may be limited by sample composition
• B. Sample size concerns
• C. Ethnic diversity is insufficient
• D. Experimental controls are lacking

Answer: (A)

Generalizability, or external validity, is about whether study findings apply to people beyond the specific group studied. When research uses college sophomore students, the sample represents a narrow slice of the population: they’re typically within a similar age range, share the college experience, and may have comparable socioeconomic and campus-related factors. This makes it hard to confidently extend conclusions to other groups—such as freshmen, seniors, nonstudents, or people from different regions or backgrounds. That limited applicability is exactly what is meant by findings’ general integrity being constrained by how the sample is composed.

The other concerns describe different threats: sample size affects statistical power and precision, not generalizability; lacking ethnic diversity is a specific facet of composition that can reduce generalizability but is narrower than the overall issue of generalizability tied to the sample’s makeup; and missing experimental controls mostly threatens internal validity—whether the observed effects are caused by the manipulated variables within the study—rather than whether results apply to other populations.