Research area trajectory refers to the path of development and progression that a particular field of research or study follows over time. It typically involves the evolution of research questions, methods, theories, and findings within a specific area of inquiry. Researchers often track the trajectory of a research area to identify key themes, trends, and advancements, as well as to examine how the field has shifted or expanded over time. This analysis can help to inform future research directions, shape funding priorities, and guide policy decisions related to the research area.