Final answer:
The method where multiple research studies on a topic are reviewed and their findings statistically analyzed is known as meta-analysis.
Step-by-step explanation:
Multiple research studies on a specific topic are reviewed and the findings of these studies are statistically analyzed in meta-analysis. This is a technique whereby the results of virtually all previous studies on a specific subject are evaluated together. Meta-analysis allows researchers to quantify and combine the results from multiple studies to arrive at a more general conclusion about a particular question or set of questions.
By contrast, longitudinal research involves following a group of research participants for an extended period of time to collect data on how they change over time. Another approach is cross-sectional studies, where a researcher compares multiple segments of a population at a single time, such as comparing different age groups to study their dietary habits simultaneously.