What factor can lead to differences in research results due to natural changes in subjects over time?

Maturation refers to the natural progression and changes that occur in individuals over time, which can significantly impact research outcomes. This concept is particularly relevant in longitudinal studies, where data is collected from the same subjects at various points in time. As participants grow older or undergo life experiences, their behaviors, attitudes, and responses may evolve, leading to variations in the research results that are not necessarily due to the intervention being studied.

For instance, in a study assessing a developmental program for children, natural maturation can influence children's performance or behavior, potentially confounding the impact of the program itself. Recognizing and accounting for maturation effects is essential for accurately interpreting the findings and determining the true effects of interventions or changes being evaluated. By understanding maturation, researchers can better design their studies and analyze data while distinguishing between actual effects and those attributable to normal developmental changes.