Factors to Consider when Choosing a Research Design

Scientific research provides new, innovative solutions to problems, as well as interesting findings about observations and questions. Accurate research findings must begin with a design that determines the overall approach and techniques that will be used. Some types of research can use more than one method, while others must be more specific. The aims of your research will determine which factors are most important in the design. Once the purpose of the research is clear, plan the design before beginning the tests or experiments.

The study base, also known as the source population or study cohort, is the group or population that you are researching. Consider who or what is the focus of your research. A review published in the journal Occupational and Environmental Medicine in 2007 notes that a study base can be quite broad for some types of research, while other research questions will require a more narrow group. For example, if you are studying the effects of pollution in a city, the study base can include any individual that resides there full-time. However, if your scientific research is to determine the effects of pollution on children with asthma in the city, this would require a more specific study base. Subject selection will also vary if you use a cross-sectional design, which compares two different base groups. In this case, your research may look at the effects of pollution on the exercise levels of children with asthma, compared to children without asthma.

The duration of the research, or timeline that the research is looking at, is another significant factor in research design. Take into account what period of time you should collect data from for your proposed study. A review from Occupational and Environmental Medicine explains that the timeline or temporal sequence of a research study can be historical -- retrospective -- or prospective, which means it is happening in the foreseeable future. If your research study is looking at causes of an illness, it will be designed to look at the medical history and past lifestyle choices of individuals who have the illness. Alternatively, prospective studies that look forward are better suited for short-term research, such as the effects of a mother's diet on birth weight and other pregnancy results.

Check whether your research design should be quantitative or qualitative. Quantitative research involves gathering and statistically analyzing information that can be measured or counted. This type of research is objective because it provides numbers as answers or results. If you are conducting a clinical trial in medicine, such as the amount of a certain drug for treating diabetes, you should use a quantitative research design. In comparison, qualitative research typically looks at open-ended questions on study topics that cannot be measured or counted. This research design fits the study of experiences, cultures, social phenomena and trends, which are more subjective. For example, if you are studying the effects of music, you might ask your study base how various types of music make them feel. As qualitative research can change according to opinions and experiences, it would not be suitable for a clinical trial on a new medication.

A research design is reliable and valid if it can be repeated with similar results. This means that the outcome of the research was not a random occurrence, but real scientific information. Your research methods and designs should be clear and easy to follow so that they can be carried out by a separate group of researchers to produce the same results. As you plan your research design, check each step to make sure that it can be entirely replicated by someone else. To ensure your design is reliable, list all the criteria that were used in selecting the study group, identify all the guidelines of the research process, list all the equipment and supplies used, and record all results accurately. Additionally, make your research design economical; research that requires fewer resources or less expensive equipment and instruments is generally more reliable.