How do experimental and non-experimental studies differ in terms of experimental control, and how does this relate to internal validity?

Analyze the degree to which the statement of the problem or purpose and research question(s) fit each study’s research design (the internal consistency between these statements), and how the study reflects the assumptions commonly associated with the positivist traditions. Consider the following:
In comparing the dissertation with the article, what similarities and differences did you notice?
How do experimental and non-experimental studies differ in terms of experimental control, and how does this relate to internal validity?
What threats to internal validity were present in the studies you reviewed?
How transparent were the authors in discussing the limitations of their studies?