The design that was traditionally used when doing research into middle age that limited the usefulness of the research is cross-sectional.
Research can be described s the creative and systematic work undertaken to increase the stock of knowledge however it can entails collection as well as organization. It should be noted that this involves the analysis of evidence to increase understanding of a topic, hence design that was traditionally used when doing research into middle age is cross-sectional. Basically, a cross-sectional study refers to a type of research design in which you collect data from many different individuals at a single point in time. In cross-sectional research, the researcher observes the variables without influencing them.In other word, as a type of observational study design, the investigator is able to measures the outcome and the exposures in the study participants at the same time.
Learn more about research at:
brainly.com/question/968894
