The terms "research design" and "research method" are often used interchangeably. For the purpose of this tutorial, they have been separated to explain the differences, and the various options for each part of the process. As used here, the research design is the strategic plan used to help determine the observational methods used to test a hypothesis. A strategic research plan puts together the various elements of an experiment in a way that ensures there is a logical sequence that addresses the hypothesis. Setting up the right design for an experiment reduces the potential variables that may create confusion in the results, ensures that the researcher can find a cause for any changes made based on the research, and incorporates proper control factors into the experiment that will measure any changes.
There are several types of designs that can be employed when deciding the best approach to research. The type of research designs is primarily determined by the question being asked, the hypothesis being presented, the subject of the study, and the variables involved. Depending on the information being sought through the research process, a study can be designed to search for either qualitative or quantitative information. Qualitative research looks for information about how people think by examining opinions and reasoning. Quantitative research gathers data from statistics that can be used to determine facts. Knowing what type of information is being examined will lead the researcher to the possible research design to use for strategically implementing the experiment. Some of these design types include:
For more information about these design types, there are a number online resources as well as a number of books on the topic available in the library, such as The Encyclopedia of Research Design.
If the research designs are the strategy used for studies, then research methods are the tactics. Most research methods are determined by the nature of the study. Once the researcher has set up a research design, the next step is to determine the best research method to use when implementing the plan. Just like research design, research methods tend to fall into two main categories: qualitative or quantitative. Quantitative methods are used with analytical studies, which primarily focus on using numerical data. On the other hand, qualitative methods are used with descriptive research and the information from this method compiles data from thoughts, words, feelings, senses, or other non-quantifiable data. Other factors such as the purpose of the experiment can help determine the best method to use for the project. If the purpose of the research is the most important factor, the researcher has to decide if the research is intended to resolve or address a problem, or to further the knowledge in a field. Knowing this information may lead the researcher to using methods that are most appropriate to either fundamental or applied research. Different research methods are more suited to different research design.
Since descriptive designs can be quantitative or qualitative, the research methods used in these studies are based on the question being asked in the experiment. The methods used in descriptive research attempts to find out what something is, or to discover causal relationships.Some of the more common methods include case studies, surveys, and observational methods.
Correlational research designs are quantitative in nature, since they use statistics to find causal relationships in variables. The methods used for these types of studies look for ways to predict how variables will interact. Cohort studies and case studies are the most commonly used methods in correlational research.
Experimental research uses statistical information gathered from experiments to determine if an intervention has an effect on the outcome. These studies use quantitative methods that examine how an independent variable changes a fixed dependent variable. Randomized control trials and controlled laboratory experiments are the most prominent methods used for experimental research.
Although quasi experimental methods are primarily quantitative, it is recommended that qualitative methods are used in tandem with these to gain a stronger understanding of the results of the study. Some of the methods used in these studies include regression based methods and differential impact estimates.