What are some reasons for using a case study approach?

Case Study Paper Instructions
There are many methods available for conducting research, one of which is a case study. The purpose of this assignment is for you to learn how to conduct and complete a case study.
Instructions: Answer the following 4 questions using current APA format throughout. This includes your title page, running head, author note, appropriate vocabulary and sentence structure, introductory statement, citations, page numbers, levels of headings throughout the document, and consistency between your citations and references. Use your course textbooks and at least 2 additional scholarly references. This assignment must have a title page, 2–4 pages of content, and a reference page. Give the answers to these questions in your own words and with your own explanation. Cite and list your various sources as references. Create your own phrase for a properly-formatted level one heading for each question so as to be clear about which item you are answering. Your headings must not be simply copied/pasted from the questions. An acceptable heading must clearly capture the essence of each question.
1.      What is a case study?
2.      What are some reasons for using a case study approach?
3.      What are advantages and disadvantages of this approach?
4.      Where, or in what ways, can a researcher acquire information/data that can be used for a case study? In other words, what are some various sources for information that a researcher can use in a case study? Note: For question 4, these are 2 ways of stating the same question; these are not 2 separate questions.
Case Study Paper Grading Rubric
Criteria
Points Possible
Points Earned
Criteria #1
0 to 50 points
Current APA format is used throughout the document. The paper must also include the following:
·         Properly-formatted title page and references (the course textbooks and at least 2 additional scholarly references);
·         The required length (2–4 pages);
·         Proper citations;
·         Introductory statement;
·         Levels of headings;
·         Consistency between citations and references;
·         Appropriate vocabulary and sentence structure; and
·         Proper structure for a case study approach.
Criteria #2
0 to 25 points
·        All 4 assigned questions are addressed.
·        Sufficient explanation for each question is provided.
·        A properly-formatted level one heading with your own phrase is present for each question.