Congress is commissioning you to prepare a study about the effects on readers of violent, disturbing literature—e.g., gothic literature such as Poe's "The Black Cat" or Hawthorne's "The Birth-Mark." You are told that among sociologists there are two schools of thought: one is that such literature acts to “purge” the violent tendencies of people, allowing them to vicariously “let off steam” in a safe environment; the other is that such literature only desensitizes people and therefore makes them more prone to violence. How would you evaluate this problem, and what recommendations would you make? What information would you need, and what resources would you have to consult? Who would you ask?

In order to verify claims—even those posited by scientists and other professionals—one must conduct fact-checking research. How would you evaluate this particular thesis? Firstly, you should find relevant scholarly articles, preferably published in peer-reviewed journals pertaining to the field (e.g., psychology, sociology, etc.). You must cross-examine the conclusion of the initial source material with the research conducted by other scholars. This is akin to seeking a second opinion from various physicians regarding a diagnosis and treatment recommendation.
The most important pieces of information you'll need are the quantitative data, qualitative data, and the researchers' methodologies in conducting their experiments. This way, you can examine any flaws or biases in their methodology which could substantially affect the conclusion of the research. To supplement your findings, it is recommended that you also take secondary sources into account, such as newspaper articles or books highlighting the issue (e.g., youth violence or the correlation between media and violent behavior).
Since the conclusion of the researchers is based on the works of particular writers, it is also important to read in-depth biographies and/or autobiographies of those particular authors. Were they prone to violence and anti-social behavior? Did their works reflect their actual lives and personalities? These are all essential questions to answer in order to verify the claims of literary or scientific scholars.