A number of different scientific methods are used in psychology, each with its own advantages and disadvantages. The different methods are best suited for answering different kinds of questions, so they tend to be relied upon to varying extents by individual methods of scientific inquiry involve description. (Benjamin B. Lohey)

In everyday life, we all observe and describe people, often drawing conclusions about why they behave as they do. Professional psychologists do much the same, only more objectively and systematically. (David Myers, 2001)

Research methods have been classified in many different ways. One simple approach which is widely used distinguishes between four main strategies; case study, survey, experiment, naturalistic observations.

Case study is a psychological study involving the detailed investigation of just one particular case, or individual. (Peter Stratton & Nicky Hayes, 1988). The individual as the case is probably what spring first to mind. Case studies are not necessarily studies of individuals, though they can be done on a group, in an institution, on a neighborhood, on an innovation, on a decision, on a service, on a program and on many other things.

Case studies are then very various. We have individual case study, set of individual case studies, community studies, social group studies, studies of organization, institutions and studies of events, roles and relationships. (Colin Robson, 1993)

The term Survey is used in a variety of ways, but commonly refers to the collection of standardized information from a specific population, or some sample from one, usually but not necessarily by means of questionnaire or interview. Generally, a relatively small amount of information is collected from any one individual, constructing with a case study, where a great deal of information might be obtained from ‘a key informant’. Surveys are well to descriptive studies where the interest is, say; in how many people in a given population possess a particular attribute, opinion or whatever. However, survey data can also be used to explore aspects of a situation or to seek explanation and provide data for testing hypothesis. (Colin Robson, 1993)

Experimental Method is the most disciplined of the methodologies used by psychologists. Using these methods an experimenter manipulates a variable to be studied, chooses the response to be measured and controls extraneous or irrelevant influences that might inappropriately affect the results of the experiment.

Information gathered in this manner is called research information. Properly conducted research satisfies several criteria such as, objective, systematic, repeatable, empirical, public and meaningful problem. (Wittig and Beklin, 1977)

Naturalistic Observation is the careful observation of events not manipulated by the observer. Like the case study and survey methods, naturalistic observation does not explain behavior. It describes it. (David G. Myers, 2001) For example: a psychologist who is interested in studying children at play might observe several children together in a playroom. Using one-way mirror, the psychologist could then observe and record the children activity without making his/her presence known. In this way, the psychologist could minimize the influence an ‘adult presence’ might have on the children. The children could do as they wish, unless for one reason the psychologist halts their play. (Wittig & Belkin, 1977)

Sociologists also use the terms I have mentioned above, in order to study their different researches concerning society and social patterns between the individuals.

Differences are not many:

Since survey involves a study of a sample of the population under study. A researcher can estimate the options and attitudes of the larger populated bases on data obtained from systematically selected sample by extrapolating his or her findings.

Experiments: Tests cause and effect relationships between two variables. The three basic steps characterize most sociological experimentation.

· Establishing two comparable groups: experimental and control groups

· Exposing the experimental group to some influence, stimulates or conditioning.

Observation: Observation of social behavior in natural settings. Researcher attempts to become part of the group.

Case Histories: Allow for more in depth exploration of issues (e.g., involve examination behavior, feelings, thoughts etc.) (L. A. Coser, S. L. Nock, P. A. Steffan, D. Spain, 1991)

There are various Advantages and Disadvantages that concern these psychological methods in psychology.

Survey: Collection of information in standardized form from groups of people.

Disadvantages

a) Data ate affected by the characteristics of the respondents.

b) Respondents wont necessarily report their beliefs, attitudes etc.

c) Typically have a low response rate.

d) Ambiguities in and misunderstandings of the survey questions may not be detected.

e) Respondents may not treat the exercise seriously.

Advantages

a) They provide a relatively simple and strain formed approach to the study of attitudes, values etc.

b) They may be adapted to collect generalizable information from almost any human population.

c) Highly structured surveys have high amounts of data standardization.

d) The easiest way of retrieving information about history of largest people.

e) Extremely efficient at providing large amounts of data, at relatively low cost in a short period of time. Although this might coinside as disadvantages, if they seduce the researcher into using survey when it may not be the most appropriate strategy to answer the research questions. (Colin Robson, 1993)

Experiment measuring the effects of manipulating one variable on another variable.

Disadvantages

Random assignment: There are practical and ethical problems of achieving random assignments to different experimental treatment or conditions. Random is also feasible in a typical circumstances or with selected respondents leading to questionable generalization.

Validity: actual treatment may by an imperfect realization of the variables of the interest, or a restricted range of outcomes may be insensitive resulting in questionable validity.

Ethical issues: strict adherence to ethical guidelines is advocated, but this may lead to losing some as the advantages of moving common sense is needed.

Control: over extranceous variables may mask the effects of treatment variables, or bias their assessment.

Advantages:

Generalization: if concerned with generalization results to real world the task is easier concerned is easier with experimentations in a natural setting.

Validity: the demand characteristics of laboratory experiments where subjects tend to do what thing you want them to do what thing you want them to do, are heightened by the artificially and isolation of the laboratory situation.

Subject Availability: it is not easier task to get subjects to come in to the laboratory. You have to rely on them turning up. (Colin Robson, 1993)

Case study: development of detailed intensive knowledge about a single case or of a small number of relative cases.

Selection of a single case of a situation, individual or group or interest or concern; study of a place in its context. Collection of information via range of data collection techniques including observation, interview and documentary analysis.

Naturalistic observation: A problem is that many observational studies is the effect of the observer on the subjects behaviours. If the observers’ presence profoundly effects the subjects action, the study might not succeed in validity testing the hypothesis. When concealment is impossible, the observer tries to blend into the background and refrains from recounting any behaviour until his/her presence taken for granted. (R.R. Bootzin,G.H.Bover, Robert B. Z., E. Hall, 1975)

All the above methods I mentioned are useful since they satisfy different purposes:

Experiments for explanatory studies

Survey for descriptive studies

Case study for exploratory purposes

And, Naturalistic Observations for individuals societies, beliefs and thoughts.