Advantages & disadvantages of qualitative & quantitative research methods

Research is divided into two main categories, qualitative and quantitative. Qualitative research is deductive in nature, providing rich information that can be used to generate hypotheses. Its focus is to reveal the essence and quality of the subject(s) of study. Quantitative research employs inductive reasoning, centring on hypothesis testing. Its goal is to quantify the subject(s) of study, making inferences about relationships between variables. There are advantages and disadvantages to both methods of research.

Qualitative research involves studying phenomena in their natural habitat, rather than in a laboratory setting like quantitative research. This yields results that are more true to life and generalisable to similar phenomena. Also, unlike quantitative research that focuses on isolating, reducing and controlling the variables involved, qualitative research obtains a holistic picture of the subject(s) of study. This provides rich information and allows for individual differences to shine through. Finally, it may be impossible or unethical to study a particular subject using quantitative research methods. The non-intrusive nature of qualitative research is an advantage in that it allows the study of such phenomena in those cases.

Because specific measurements and objective data are not the focus in qualitative research, biased information is a problem. The disadvantage of subjectivity is that results are dependent upon the researcher's interpretations and descriptions. Also, when surveys are used, the data collected can be inaccurate because respondents are often untruthful or biased. Also, unlike quantitative research that controls as many variables as possible, qualitative research has very little control; therefore, "confound" variables are a problem. Results found may be due to many other factors that researchers did not consider or even know. Lastly, the replication of results is much more difficult -- and in some cases even impossible -- in qualitative research.

The number of confound variables is significantly less than in qualitative research, because the laboratory setting promotes the isolation and control of the variables studied; replication of results is easier because of this as well. Also, the use of random assignment when placing participants in to different treatment groups greatly contributes to the objectivity of the results. Also, a quantitative research methodology often allows researchers to identify a cause and effect relationship. Another advantage is that quantitative data reveal measurements that provide meaningful information about the subject(s) of study. The numbers and statistics used in quantitative research allow one to make inferences and evaluations about the subject(s) of study.

Results found in quantitative research are not necessarily applicable to similar phenomena found in the real world, as research is conducted in a laboratory setting; therefore, generalizability is low in quantitative research. Demand characteristics are an issue, because participants in a quantitative research study will act differently because they are being studied and in an unfamiliar environment. Another disadvantage is the results centre on identifying trends and norms. Individual differences are not appreciated, nor are they desired; researchers in this setting do not want statistical outliers skewing their data. Finally, confound variables are still present even though quantitative researchers focus on tightly controlling the environment.