Advantages and disadvantages of quantitative and qualitative research

The research is defined as a dynamic activity with the aim of building an increasing patrimony of knowledge. The scientific method is the modality with which the science investigates the reality, and is the most well-known way in the process of knowledge definition.

Since the first average of XIX century, the current of positivism, characterized by scientific progress exaltation, boosted the scientific research through the use of standardized tests, systematic observations, experiments, measures, the collection of data, statistical analysis (application of the quantitative method) (Kroeze, 2012). However, in recent years, new approaches to the scientific method have arisen. The interpretativism, that analyses the subjective meaning of social problems, events or practices, through the collection of non-standard data, as texts, images, and fewer numbers and statistics, opens up the road to be applied also in the scientific field. According to the interpretative approach, anyone is able to predict actions nor generalize since the complete separation of the researcher and the object of the study is impossible (application of the qualitative method) (Hammerslay & Traianou, 2012). The Grounded Theory, a methodology that belongs from this second approach, differs from the quantitative methods since it doesn’t assume any hypothesis to demonstrate through the voluntary perturbation of the studied system (scientific experiment), but it consists in the observation without prejudice nor altering the studied system, in order to collect information. Narrative Medicine is among those disciplines that apply qualitative research since it follows the principles of Grounded Theory.

From these definitions, not only differences between the two approaches emerged, but also some important points in common, the methodological basis of the scientific research, in general. Firstly, the research must lead to innovation in those fields where human beings have not already arrived. A thin ideological borderline exists, called frontier of science, a place of questions still without an answer, and that experts try to explore. The Science must also renovate itself, so what is considered a scientific true nowadays could be denial tomorrow by new evidence. The scientific ‘alphabet’ consists in data, measures, and statistics, that lead and show conclusions of the study or of the project.

Although both the quantitative-Evidence based medicine and qualitative-narrative research have the same dignity from the scientific point of view, the extremism of some members of the scientific community stirs up the polarization of the research and the distance from the narrative method. It happens because the latter is often wrongly considered a non-scientific approach, and its results were considered as influenced by the researchers’ subjectivity. Actually, the subjectivity, no matter how much efforts we’ll do, is intrinsic in human nature, so it is impossible to be eliminated, even in the quantitative methods. For example, Prof. Heisenberg, father of the modern chemistry and author of the uncertainty principle, that says: for a particle of the atom, it is not possible to measure, and so to actually know, a specific value of the position and movement quantity at the same time and with zero uncertainness. According to this principle, indeed, at the moment of researcher observation of an electron, an activity that requires a great quantity of Energy, the electron will absorb the energy, changing its position or speed. This is just an example among many from which we can deduce that each tentative of altering the world, the object of our scientific investigation, it is not really possible not to do errors; so, the objectivity that the scientific community vaunted is not actually possible at any level, and independently by the methodology, whether quantitative or qualitative it is.

Among the advantages of quantitative method, the possibility to reach a higher samples size is the most important one. In this way, indeed, it could be possible to better generalize conclusions, since the latter could be considered more robust and trustworthy. Further, statistic analysis software could reduce the time of the data analysis, focusing on few variables of interest (Carr, 1994). However, this approach generally doesn’t consider the deeper meaning of the social phenomena, and it is not able to measure the way in which the society change, or the way people interpret their actions and of others. Several variables, impossible to be measured with numbers actually exist – for example, measuring the deeper significance of an educational course is hardly quantified. Briefly, the quantitative methodology shows a single moment, a picture, of phenomena, with no dynamics and poor of details (Schofield, 2007).

“Everything that can be counted does not necessarily count; everything that counts cannot necessarily be counted” (A. Einstein)

On the contrary, the qualitative approach has the advantage of producing a great number of details, that is not easy to collect with quantitative studies, such as participants’ emotions, opinions, experiences, and perspectives, through the interpretation of actions and meanings; further, this method is the optimum for comparing different points of view on the same phenomenon, as the investigation of illness, perceived by not only the patient who suffers from that disease, but also by their caregivers and providers of care. It could be also said that the qualitative methodology is holistic since it comprehends the social, cultural, values and personal contexts analysis of the phenomenon they are studying, adding meanings to the quantitative number. Consequently to the flexibility of the qualitative analysis, also very complex phenomenon could be easier to understand, such as the relation of care between patients and doctors (Denzin, 1989). The Narrative Medicine could be so considered a valid tool to add meaning, details, and amplify the medical-scientific horizon on those fields of difficult application of quantitative research, as the living with illness.

Although the pros here described, we must report also several possible limitations to this approach: first of all, the qualitative method is particularly diffused and appreciated in psychological and social fields, but it is not already known in the medical sector, where Stakeholders are often supporters of the Evidence based medicine. One of the major critics addressed to the qualitative method by EBM concerns the numerours of data collected from the samples, than the quantitative method.Indeed, the analysis of such a reach and detailed sample requires generally more time and software are few in this case. Furthermore, this method is often considered subjective for the interpretation of data. However, the richness in details compensates the smaller number of data, and the three blind analysis bring objectivity to the interpretation (Silverman, 2010). So, through the narrative medicine, it is possible to obtain, although longer work, quantitative and objective data, like as pattern of recurrence in the narratives, and quantify feeling, living, emotions, a need of the different actors involved in the disease, patients, families, and doctors, without altering the studied objective, but limiting us to observe.

In conclusion, in this article, we would like to carry out a critical analysis, showing the pros and cons of two scientific methodologies, the qualitative and the quantitative research. Although we cannot declare any one of the two approaches as ‘better’ than the other one, in the Life Science field  the evidence-based medicine has dominated for a too long time against the other one. The risk, however, is to lose important data. The integration of the two approaches could, consequently, close the gap of this recent years.

Silvia Napolitano

Researcher at Healthcare Area of ISTUD Foundation. Master degree in Industrial Biotechnology at University of Milano-Bicocca, Post-graduate ‘Scienziati in Azienda’ at ISTUD Foundation. Expert in Medical Writing, especially in areas as the qualitative research and Narrative Medicine. She contributes to research and educational projects with the aim of improving the quality of life and quality of care of patients with chronicle or genetic diseases.

This Post Has One Comment

  1. Jean Paul Nemerimana

    Good article !
    But how I would love to read an exhaustive list of advantages and disadvantages of both research approaches!

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