
Types of research design:
Below some types of research design and their characteristics have been mentioned. It should be noted that each type of the research design has its own advantages and disadvantages. The researcher does not select a research design because it has several advantages but because it is most suitable types of research design for his study. Some types of research design are most suitable for the field of medical science, other types of research design are suitable for marketing, other for psychology and behavioral sciences. So the researcher should have knowledge of all types of research design before selecting one for his study.
The cross-sectional study design
The cross-sectional study designs are most commonly used in social sciences, behavioral sciences and marketing. In cross-sectional study design, the researcher aims at finding out the characteristics of a population by taking a cross-section of that population. The study is conducted once by taking a cross-section of the population. The method of designing this study is simple, the researcher determines the population to be studied and draws a sample from that population. The respondents are asked question using any one of the social science data collection tools. The answers of the respondents reflect the attitude of the respondents towards some service, idea or situation. The cross-sectional study is conducted once so there is no before-and-after study involved in it.
There are various advantages of cross-sectional study design: Cross-sectional studies are relatively easy to conduct and they are easy to analyze, they are conducted at one time so they are not time-consuming, the sample can be drawn using any of the appropriate methods. The drawback is that in cross-sectional study design the researcher cannot determine the pattern of change before and after the test. The study is conducted once, therefore, the researcher cannot determine any change in the observations of the population.
The before-and-after study design


The longitudinal study design

The major disadvantage of the longitudinal study is that the respondent might lose interest and he may give responses that do not truly represent his thinking. The other disadvantage can be that the population may not remain same and this will affect the results. However, in certain fields, longitudinal study is very effective to conduct because it determines the change pattern over a period of time.
The retrospective study design
The retrospective studies as the name suggest studies a prevalence of a situation, phenomenon, or an issue that has happened in the past. It is a descriptive study and it uses the available information from the past in the form of books, magazines, journals, newspapers, government records, diaries or letters. Sometimes if the person who encountered that situation can also be asked for the information to conduct a retrospective study.
The retrospective study design has its own advantages and disadvantages. A retrospective study design is a descriptive study design, hence, it can be used only to investigate about some topic descriptively. This study uses secondhand information or secondary sources so the reliability of the information is not much. The reason for conducting a retrospective study is that in the absence of primary data, the researcher cannot use any other method to collect the evidence
The prospective study design
The prospective study design studies a situation, phenomenon or a problem that might occur in the future. The prospective study design is like retrospective study design, but it focuses on predictions about the future rather than about the past happenings.
The retrospective-prospective study design
The retrospective-prospective study design studies a situation, event or a phenomenon as it happened in the past, in addition, it forecasts about the same situation if it happens in the future.
The experimental study design

These are few major types of research design and there are several other minor types of research design that are used in specific studies.