Final answer:
The number of reported grandmother deaths around exam time, used by Prof. Adams to measure death rates, is a proxy with potential measurement error and may not accurately reflect the actual incidence of such events.
Step-by-step explanation:
Prof. Adams measures grandmother death rates by counting the number of students who report that their grandmother has died. However, he needs to keep in mind that the number of reported deaths is just a proxy that is capturing the actual incidence of grandmother deaths with a great deal of measurement error. This means that the proxy may not accurately represent the true rate of grandmother deaths, as it could be influenced by students falsely reporting deaths for various reasons, including seeking extensions or sympathy surrounding exam periods. The notion of heightened death rates due to stress is based on observations of the physiological impacts of extreme stress on cardiovascular health, which are well-documented in numerous studies.