This essay will look at difference between to research methods; Case Study and Observation. Case study is the understanding of the complex issues or can extend experience or add strength to what is already known through previous research. It is an in-depth study of an individual, group, incident or community. Case studies emphasize on the detailed analysis of the event or conditions and their relationship. Sometimes researchers use the case study method for real life situations and use sources of evidence to prove their study. First step to take in case study is to collect all data about the case and should be organised to draw attention to important points in the case. The case study's questions are most likely to be information questions "why "and "How "therefore these questions are helpful to focus on the study's goal. In case study researchers gather facts from different sources and conclusions is made of these facts. Here is a case study of the David's behaviour," David, 13 year old who has been admitted to a detention facility in California. Police reports indicate that he and another boy were arrested for breaking and entering into a private residence. David grew up in an upper middle class section of California. David's father is a professor at a college, and his mother, is a dentist who works for a health care group. Even as a small child, David seemed unable to restrain himself. He would bound around the house, crashing into walls and objects, frequently breaking items or destroying house plants. David entered puberty at the age of 11, and at that time, his behaviours became more destructive. He frequently got in fights with his classmates, and would verbally assault teachers. His parents suspect that he may have tried smoking cigarettes and may have experimented with sniffing glue. After his arrest for breaking and entering, David began to cry and told his parents that he felt badly for what he had done. He added that he was unable to control himself."