One of the oldest methods of research is the case study, in which psychologist study one or more individuals in great depth with the hope of an accomplishment of revealing true to all persons. Sigmund Freud came up with his theory of personality from a series of case studies. Case studies can be misleading, unrepresented knowledge of the individual can lead to a false conclusion.
The survey method is commonly used in correlation and descriptive studies. A survey is less in depth than the case study. Surveys ask people to tell about their own opinions or behavior. When asking questions one must be careful of how the question is worded, this can be known as wording effects.
The representative sample is the only way to get an accurate picture of the attitudes and experiences of an entire population. They key point in sampling is to remember that the best way to base a generalization is not to use the exceptional cases in extremes. A population is all the cases in a group in which experiments or samples may be used for a study. A sample that fairly represents a population because each individual in the study has in equal chance of being included is known as a random sample. Another research method is the descriptive method known as naturalistic observation. This method involves observing and recording behavior in a situation that is occurring naturally without any manipulation. This method can range anywhere from observing animal societies in the jungle to interactions between a parent and their child. This method in 1999 enabled Robert Levine and Ara Norenzyan to define pace of life as walking speed, the speed with which postal clerks completed a simple task and the accuracy of public clocks.
The first step towards predicting behavior is describing it. In order for a trait or behavior to correlate, the trait or behavior must accompany one another. The statistical measurement of the extent in which two variables vary together