Qualitative and quantitative research have both advantages and disadvantages.

Selecting the best research method allows you to successfully answer a research question or test a hypothesis. Missteps at the onset of the research process may derail an otherwise promising study. Knowing the advantages and disadvantages of quantitative and qualitative methods will help you make a better decision. Both methods are quite useful depending on the type of study. Some dissertations and research studies take a mixed method approach, which incorporates qualitative and quantitative methods in different phases to obtain a broader perspective.

Quantitative Advantages

You may be very familiar with quantitative research from your science classes where you learned and practiced using the scientific method. A problem or question is examined by deductively forming a hypothesis derived from theory. Controlled, objective testing and experimentation ultimately supports or rejects your hypotheses. Each step is standardized to reduce bias when collecting and analyzing data. A big advantage of this approach is that the results are valid, reliable and generalizable to a larger population. Quantitative research is advantageous for studies that involve numbers, such as measuring achievement gaps between different groups of students or assessing the effectiveness of a new blood pressure medication.

Quantitative Disadvantages

While quantitative research methods work well in the laboratory under tightly controlled conditions, measuring phenomena like human behavior in natural settings is trickier. Survey instruments are vulnerable to errors such as mistakes in measurement and flawed sampling techniques. Another disadvantage is that quantitative research involves numbers, but some topics are too difficult to quantify in numbers. For example, constructing an effective survey with closed-ended questions about how people fall in love would be difficult.

Qualitative Advantages

Qualitative research is often used to conduct social and behavioral studies because human interactions are more complex than molecular reactions in a beaker. Subjectivity, nonrandom sampling and small sample size distinguishes qualitative research from quantitative research. A big advantage of qualitative research is the ability to deeply probe and obtain rich descriptive data about social phenomena through structured interviews, cultural immersion, case studies and observation, for instance. Examples include ethnography, narratives and grounded theory.

Qualitative Disadvantages

Qualitative studies often take more time to complete due to the pain staking nature of gathering and analyzing field notes, transcribing interviews, identifying themes and studying photographs, for instance. Studies are not easily replicable or generalizable to the general population. Conscious or unconscious bias can influence the researcher’s conclusions. Lacking rigorous scientific controls and numerical data, qualitative findings may be dismissed by some researchers as anecdotal information.

Mixed Methods

A mixed method approach capitalizes on the advantages of the quantitative and qualitative methods while offsetting the drawbacks of each. For instance, a principal interested in building rapport with parents of school children might undertake a mixed method study. First, the principal would send out a school climate survey to parents asking them to rate their satisfaction with the school and quality of instruction. After analyzing the data, the principal would identify areas needing further exploration such as parent complaints about the school’s response to bullying incidents. Focus groups could then be organized to gather qualitative information from parents to better understand their concerns.