What method was used by the characters in the film to gather data?

Guidelines/Instructions for the film Critique
Write a three-page double spaced analysis critique on the film Erin Brockovich. The paper should be no more than three pages. The three pages do not include title page, abstract, or reference pages. Use the areas listed below as headings or topics of each paragraph you writeComponent of the film critique analysis on Erin Brockovich:
Discuss survey research.

How was a needs assessment conducted by the researcher in the film?
How was the needs assessment used to obtain information about the prevalence, distribution, and interrelations of variables within the affected population?
Discuss ethical implications about the researchers actions.