Final answer:
Florence Nightingale's actions that formed the foundation for modern-day nursing research methods include collecting data systematically on the health status of British soldiers during the Crimean War.
Step-by-step explanation:
Florence Nightingale's actions that formed the foundation for modern-day nursing research methods include collecting data systematically on the health status of British soldiers during the Crimean War. Nightingale kept meticulous records regarding the causes of illness and death during the war, which later became the science of epidemiology. Her analysis of the data she collected was published in 1858, which led to many reforms in the British military's system of medical care.