Types of Research Method
Even though there are numerous types of research designs; the following are the major categories: descriptive, correlational, historical and experimental. Many factors influence the type of research design or method that is more suitable in answering a given research question. The following is an overview of the difference between these research categories.
According to Kothari (2008), descriptive research method is where the investigator employs observation and description of the subject without influencing it in any way. In other words, descriptive research entails describing and interpreting conditions, events or situations of the present. Conclusions are drawn from this type of research only applies to a population or sample under study. This type of research is also characterized by the following elements: broad research questions are usually used, after providing a descriptive analysis of the population or sample it leaves inference to the readers. This method of research is vital in obtaining a general overview of the subject.
According to to Sidman (2005), this method of research can take the form of questionnaires, case studies or surveys. An example of this kind of research is the social case study of an individual subject which allows observation without affecting or influencing the behavior of the subject. This type of research can be employed by market researchers in judging the habits of the customers or companies. The results obtained from a descriptive research cannot be used to as a definitive answer to disapprove a hypothesis but with the proper understanding of the limitations, this type of research can be indispensable in scientific areas of research. For instance, descriptive research can be employed as a pre-cursor to quantitative to quantitative research designs by providing a general overview of valuable pointers that are worth testing quantitatively (Gabriel et al, 1992).
On the other hand correlation research is a quantitative research where two or more quantitative variables are obtained from the same group of population in order to determine if there is any relationship between the variables. In other words, this type of research evaluates or examines the covariation of two or more variables. Therefore the purpose of this type of research is to determine if the variables relate to one another, to make the prediction of a variable using another and to identify possible cause and effect relationships between a given sets of variables. In other words; this form of research method is employed in revealing the systematic relationship between descriptive parameters (Kothari 2008). An example of this type of research is determining the covariance between cigarette smoking and lung diseases. The two variables, that is; cigarette smoking and lung disease are examined to find if they covary together. Like observational research, no data is manipulated in correlation research. Null hypothesis are frequently employed in this kind of research (Gabriel et al, 1992).
According to Kothari (2008), historical research is a descriptive that is based on secondary data analysis to describe and interpret events, situations and conditions of the past. In other words, historical research is the process of systematically analyzing past events to give an account of what happened in the past. This method involves studying the past as a prerequisite of understanding the present and planning for the future. This research entails in-depth analysis of source materials such as historical literature and archival literature. This type of research method is characterized by the following elements: mostly qualitative data is presented, rich descriptive narrative and broad research questions. This type of research cannot be manipulated since it relies on data from the past. The main objective of this research is to communicate an understanding of past events. An example is; carrying out study on historical trends in a given industry so as to have a more comprehensive picture that will be vital in formulating strategies in a company (Gabriel et al, 1992).
Experimental research method can be defined as a collection of research designs that employ manipulation and controlled testing in order to develop an understanding of causal processes. In this method, one or more variable is manipulated to determine its effect on a dependent variable. Therefore this method is employed in predicting phenomenon (Sidman, 2005). In this method, the participants in a research are randomly assigned to groups. In order to determine the causal model (the underlying cause of a particular phenomenon); each group is treated differently and measurements are taken to determine if each treatment appear to lead to a different outcome. This research method is characterized by the following elements: randomized selection and assignment of subjects, the researcher manipulates the independent variable; also in this method, the researcher goes beyond description and prediction and attempts to explain what caused effects. An example of this experiment is a social psychology experiment carried by Stanley Milgram based on the research question “Will people obey orders, even if they are clearly dangerous?” Another example of this type of research is market tester (where a new product is introduced in randomly selected locations which give a representation of the whole population) (Kothari, 2008).