There are two main investigation methods in the research field: quantitative research and qualitative research. These two methods can exist separately, and they can complement one another, all according to the field researched in the framework of the doctoral work.

In the doctoral work quantitative research is generally used in the exact sciences, natural sciences, and social sciences, when the researcher seeks to examine defined attitudes in a quantitative manner. In quantitative research the researcher must examine quantitative and numerical data, and the results constitute the research findings. Quantitative research examines the overt behavior of people, and through it creates a mapping of the phenomenon – a quantification of the phenomenon, direction, and trend.

In contrast, in the doctoral work qualitative research is primarily used in the social sciences, behavioral sciences, and humanities and primarily engages in human behavior. It searches for explanations for existing behavior. This is descriptive and interpretative research that attempts to achieve a subjective understanding of the research subject, generally without a prior hypothesis but through learning and experience. Qualitative research can be performed not only with people but also with the texts they have left behind: testimonies, letters, students’ essays, and so on.

The very definition of the types of research indicates that quantitative research in the doctoral research is primarily objective, since it analyzes the research results in a rational, numerical manner, without the researcher’s emotions. Qualitative research in the doctoral research, which addresses people, examines subjective information and is based on the researcher’s emotions and thoughts.

The research instrument in the quantitative method in the doctoral work is for the most part a closed questionnaire distributed to a large number of research subjects, and the researcher bases his results on statistical analyses. The qualitative method in the doctoral work is based on a number of research instruments: interviews, observations, action research, participative observation, case study, narrative research, and open questionnaires.

These two approaches lead us to discuss the advantages and disadvantages of each one of the methods in the doctoral work. The great advantage of quantitative research is the ability to involve a large number of research subjects, and a large research population can lead to more reliable results. Hence, the primary disadvantage of qualitative research generally is the low number of research subjects.

The proponents of quantitative research argue that the objectivity of quantitative research gives it a great advantage. However, the proponents of qualitative research claim that without the researcher’s intervention it is not possible to reach the depth of the social discourse required in the Ph.D. framework but only to measure the relations.

Qualitative researchers speak about the study of culture and ethnicity that cannot be measured using quantitative instruments, where the definitions are short and precise and cannot bring the researcher to an in-depth understanding of the culture. The formulation of the pre-defined responses forces the research subject to choose one of them, even if it is not precise for him and perhaps is not defined according to his scale of values. An in-depth interview of the same research subject enables the researcher to reach the understanding of how the research subject defines the different concepts and whether they are relevant to him.

The great advantage of quantitative research is the researcher’s lack of influence on the research subjects. The researcher does not participate and does not exist in the research field, and this creates the maximum objectivity. In contrast, qualitative research is subjective, and every interaction may influence the research results, thus directly harming the doctoral work.

When is it acceptable to use quantitative research?

• When it is important that the research be conducted simultaneously in different geographic regions.

• When there is access to a large number of research subjects.

• When the topic allows the use of a questionnaire.

• When there is no need to understand processes but to present their data.

• When it is possible to sample the population statistically.

It is acceptable to use quantitative research primarily in the natural sciences, exact sciences, psychology (behavioral sciences), and economics.

When is qualitative research used?

• When it is necessary to understand processes and sequence of events (for instance, processes of decision making, emotional processes).

• When the population is too small and there is low access.

• When the research topic is too sensitive or intimate to be asked about in a questionnaire.

• When the research questions are still not clear (exploratory research).

• When psychological depth and insights are needed, which quantitative research cannot supply.

• As support and explanation for a parallel or preliminary quantitative research.

• When it is not possible to sample the research population statistically.

• When the research population cannot answer the questionnaires.

It is accepted primarily in the humanities (history, Bible, literature, etc.), in art, in design, etc.

Quantitative research in the doctoral work:

• Is used primarily in the natural sciences, economics, and management and also for people.

• Describes the existing situation.

• Addresses facts, numbers, measurement, hypotheses, and proofs.

• Attempts to anticipate what will happen in the future in similar cases.

• The researcher is outside of the research.

• Is informative.

• Searches for rules.

 

Qualitative research in the doctoral work:

• Is used primarily in the behavioral sciences – addresses people and human behavior.

• Explains the existing situation.

• Addresses opinions, evaluations, perceptions, understanding of things in their context.

• Describes reality.

• The researcher is found in the research.

• Is interpretative, provides personal interpretation.

• Addresses emotions, feelings, values.