whats the difference between experiments, surverys, and observational studies. How can you tell what your looking at. Are the conditions of each different?
Experiments impose treatments on the subjects, where as observational studies do not impose any treatment but simply observe responses. Surveys involve asking questions to randomly selected subjects, and conditions are only used in inference tests or confidence intervals.
Experiment - treatment imposed and random assignment
Survey - verbal or written set of questions
Observational study - collecting data thru observation (prospective or retrospective)
Conditions are similar (Random, Independent, Normal)
But the context and sampling method must be kept in mind!