Observational research: It is a non randomized research, which observes and records the characteristics of the research object in the natural state, and describes and compares the results.
Experimental research: It is an analytical research that artificially carries out intervention measures and collects results.
Experimental research is artificial research, and observational research is natural research.
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(1) The basic elements of observational research: one is the research object, and the other is the research factors. In descriptive research, research factors are influencing factors; In analytical research, research factors are called risk factors or exposure factors.
(2) Summary of characteristics of observational research: In the study, no experimental factors (intervention factors) are imposed on the subjects, and the subjects can be grouped according to certain characteristics, but no random grouping is required.
(3) Experimental research is to manipulate the change of a certain variable under the control condition to study the impact of the change of this variable on other variables.