Descriptive statistics and inferential statistics Descriptive statistics refers to the branch of statistics of describing, as the name suggests, the basic statistical features of a given set of data. It involves ways of obtaining certain measures on a set of data and representing the information to provide some kind of visual impression. In addition, it forms the basis for quantitative analysis. The measures of central tendency like mean, mode, and median and the measures of dispersion like standard deviations are used in descriptive statistics (Shaughnessy, Zechmeister & Zechmeister, 2009, p239). Generally, measures of central tendency give the value around which a set of data is concentrated, while measures of dispersal describe how data is spread around the mean. The descriptive statistics are used when we are only interested in shedding light on the state of the data. For instance, the total number of patients that visited a psychiatrist due to psychological disorders in one week was recorded to be 56. In the research report, it would be reported that the mean number of patients with the psychological disorders is 8. This implies that on the average, eight patients are admitted but of course with some deviations. On the other hand, inferential statistics involves the analyses of the data that has already been provided to derive some conclusion that are not within the scope of the measures given (Shaughnessy, Zechmeister & Zechmeister, 2009, p255). Inferential statistics is used when we want to obtain or seek to inquire information that is not provided by the descriptive statistics. A researcher would be seeking to know if individuals performing stressful duties are more vulnerable to physical illnesses. After performing the relevant tests for association and correlation, it would be reported in the research paper that there is an observed degree of correlation between the kind of stressful tasks performed and the cases of physical illness recorded. The inferential statistics relies on the basic information that is obtained from the descriptive statistics. Most of the analyses involved in inferential statistics will need measures like the mean and the standard deviations of a given set of data (Shaughnessy, Zechmeister & Zechmeister, 2009, p240). In essence, the inferential statistics attempts to make conclusions concerning a given set of data to a more general condition. On the other hand, descriptive statistics will be handy again in interpreting the results from inferential statistics (Shaughnessy, Zechmeister & Zechmeister, 2009, p300). Case studies and single –subject experimental research designs A case study involves a research carried out on an individual. It entails the description and analysis of the individual with respect to the variables under study (Shaughnessy, Zechmeister & Zechmeister, 2009, p.324). The data that is used in the case study research method can be obtained primarily through an interview, observation or mailed questionnaires or it may be obtained from secondary sources. The case study provides a psychologist with a special criterion for studying and understanding the behavior of individuals. It differs from the experimental methods particularly due to its goals an