Final answer:
Surveys collect data through questions, experiments manipulate variables to test effects, and observational studies record naturally occurring phenomena without manipulation. Observational studies can be preferable due to ethical concerns, cost, and scalability. Models in human biology serve as ethical and practical tools for studying complex phenomena.
Step-by-step explanation:
Understanding Research Methods
Distinguishing between surveys, experiments, and observational studies is crucial for understanding how researchers collect and analyze data in social studies. A survey involves collecting data from subjects who respond to a series of questions, typically through questionnaires or interviews. An experiment involves the manipulation of an independent variable to determine its effect on a dependent variable, often including control groups and random assignments, such as the example of the aspirin study provided. On the other hand, an observational study measures characteristics without manipulation of variables, therefore cannot establish causation, but can reveal correlations within the data collected.
Three possible reasons for doing an observational study are as follows: It may be the only feasible method for certain research questions when experiments are impossible or unethical, it is generally cheaper and easier to conduct than an experimental study, and it usually can study more subjects to obtain a larger set of data.
In human biology research, models are commonly used because they allow scientists to simulate biological processes and study complex phenomena in a controlled and repeatable manner, thus providing valuable insights without the need for direct experimentation on real organisms, which can sometimes be unethical or impractical.