Need two paragraph answer for each question each question needs a different reference for each question.

1. Provide examples of experimental and nonexperimental research design. Contrast the levels of control applied to each. (two paragraphs and two sources)

2.What is sampling theory? Describe it and provide examples to illustrate your definition. Discuss generalizability as it applies to nursing research. (two paragraphs and two sources)

3. Extraneous variables may have an influence on the dependent variable. In what ways do researchers attempt to control extraneous variables? Support your answer with current literature. (two paragraphs and two sources)

4. Describe the levels of evidence and provide an example of the type of practice change that could result from each.(two paragraphs and two sources)