According to Jenkins-Smith, et al. (2017), a research design is the set of steps you take to collect and analyze your research data. In other words, it is the general plan to answer your research topic or question. You can also think of it as a combination of your research methodology and your research method. Your research design should include the following:
There are two types of research designs:
When considering your research design, you will also need to consider your study's validity and any potential threats to its validity. There are two types of validity: external and internal validity. Each type demonstrates a degree of accuracy and thoughtfulness in a study and they contribute to a study's reliability. Information about external and internal validity is included below.
External validity is the degree to which you can generalize the findings of your research study. It is determining whether or not the findings are applicable to other settings (Jenkins-Smith, 2017). In many cases, the external validity of a study is strongly linked to the sample population. For example, if you studied a group of twenty-five year old male Americans, you could potentially generalize your findings to all twenty-five year old American males. External validity is also the ability for someone else to replicate your study and achieve the same results (Jenkins-Smith, 2017). If someone replicates your exact study and gets different results, then your study may have weak external validity.
Questions to ask when assessing external validity:
Internal validity is when a researcher can conclude a causal relationship between their independent variable and their dependent variable. It is a way to verify the study's findings because it draws a relationship between the variables (Jenkins-Smith, 2017). In other words, it is the actual factors that result in the study's outcome (Singh, 2007). According to Singh (2007), internal validity can be placed into 4 subcategories:
According to Jenkins-Smith (2017), there are several threats that may impact the internal and external validity of a study:
Threats to External Validity
Threats to Internal Validity