According to Dr. Angela Velez of Davenport University, the limitations of qualitative analysis include issues with external validity, time constraints, human error and value-driven results. Qualitative analysis does not rely on statistical methods to analyze results and make correlations or provide causation.
The small sample size typical of qualitative studies limits generalizations and external validity of the findings, according to the University of Southern California. This limits the scope of the research as it is difficult to assess the impact the research has on real world situations. It also takes more time to gather qualitative data. Interviews and focus groups take hours to produce results. Quantitative methods provide reliability of data because researchers implement controls that limit bias. Without these controls in place, qualitative research is open to criticism of validity. According to Central Washington University's Dr. Stephen Jeffries, qualitative studies run the risk of subjectivity. There are also professional limitations to qualitative research. Within many disciplines, qualitative studies do not receive the academic support or opportunities for journal publication as quantitative studies do.
Types of qualitative research include observations, interviews, ethnography, historical accounts, case studies, focus groups and content analysis. Quantitative analysis involves experiments, surveys and other measurable data.