Research Methods

Research methods are the strategies used to obtain the data that will serve to answer the research problem.

Depending on the problem to be addressed and its possible solutions, there are 15 different research methods. These research methods can use the quantitative research model, which is based on numerical data, or the qualitative model, which bases its analyzes on descriptive data of the phenomena.

A mixed research model can also be used, where the procedures of the two previous models are combined. Here are the main research methods in the natural and social sciences.

1. Experimental method

The experimental method is a type of quantitative research method, where the researcher manipulates the conditions in a controlled system, and measures the effects that said manipulation has on that system. The numerical data are then analyzed by statistical methods.

For example, to demonstrate that a gene therapy technique can be used in the regeneration of mouse optic nerve cells, a group of researchers used the experimental method.

2. Randomized controlled trial

The randomized controlled trial is a quantitative research method. It is used to evaluate the effectiveness of a treatment, drug or intervention, comparing the effects between them. Research participants are randomly separated into each treatment group.

The study groups are followed for a specific period of time. At the end of the study, measurements are made for each group and the results are analyzed.

For example, if you want to compare two caries treatments, A and B, a sample of the population is taken and they are randomized to receive one or the other treatment. When the study ends, the progress or not of cavities in each group is measured. Treatment of the group with the least cavities will be the most effective.

3. Meta-analysis

Meta-analysis is a quantitative research method that analyzes the results of previous quantitative research. It is the “analysis of analysis.” It is mainly based on searching databases of research related to a certain topic, to group the results and re-analyze them and obtain new conclusions.

Meta-analysis is widely used in medical research, social sciences, astronomy, zoology, veterinary medicine, among others. Its main advantage is to increase the power of statistical analysis by increasing the number of data, without the need for new research from scratch.

For example, to investigate the effect of saturated or unsaturated fats on coronary heart disease, a group of researchers conducted a meta-analysis, looking for papers published in June 2009 in various databases of the medical literature.

From this search, they found 346 articles, of which they ultimately chose 8 papers, which in total, added 13,614 participants and 1,042 cardiac events. The researchers were able to conclude that the consumption of unsaturated fats significantly reduces the occurrence of cardiac events, a finding that the individual studies could not demonstrate.

4. Interview

The interview is a qualitative research method that is based on obtaining information directly from the person’s verbal account. The researcher becomes an interviewer and data collector. It is used with preference in research in sociology and anthropology.

There are three types of interviews: structured, individualized and semi-structured and unstructured. In structured interviews , questions are asked in identical terms to all participants to ensure that the results are comparable.

Individualized interviews are flexible, dynamic and set up as an in-depth conversation between interviewee and interviewer.

Semi-structured interviews seek to investigate specific information and contrast it with other interviews.

For example, one study conducted semi-structured interviews with 31 recently homeless people and classified the reasons for this condition in the words of those affected.

5. Ethnographic method

The ethnographic research method is a qualitative research method that seeks to investigate the living conditions of a certain group of the population. This is the preferred method in anthropology.

For example, to explore the beliefs about domestic salt and its applications in a community of agricultural workers of Latino origin living in California (USA), an ethnographic study was carried out. How the community has access to salt was observed, with interviews with key informants such as restaurants and grocery store managers, community doctors and civic leaders.

6. Focus groups

Focus groups are forms of group interviews that capitalize on communication between research participants to generate data. This means that instead of one researcher asking each person in turn, the participants are encouraged to talk among themselves, ask and exchange anecdotes, comment on the experiences and life points of the others.

For example, in a study to explore the phenomena associated with television series marathons and their relationship with compulsive behaviors, 7 people were recruited to form a focus group to share their opinions about their hobby.

7. Meta-synthesis

Meta-synthesis is a qualitative research method that seeks to analyze a group of previous research on a certain topic. It is the qualitative version of the quantitative meta-analysis.

For example, one study explored and categorized the fears of cancer in the general population. In this research, 5077 studies were analyzed, of which 102 works from 26 countries published between 2005 and 2015 were chosen, where more than 3500 people participated.

8. Observational method

Observation is the oldest of the qualitative research methods, as it uses sensory impressions for the explicit purpose of learning about a phenomenon.

The main uses of observational methods include determining the incidence and prevalence of a disease, aspects related to the causes of a disease, and the application of diagnostic tests in the clinical context.

9. Systematic review

Systematic review is a research method that can be both quantitative and qualitative, depending on the objective of the research. Many systematic reviews contain meta-analyzes, but they are not inseparable. They are used in both the natural and social sciences.

The systematic review is not a simple review or monograph on a topic. Systematic methods are used to minimize bias, thus providing more reliable findings from which to draw conclusions and make decisions than traditional review methods.

In the systematic review, a set of objectives is established, the studies are chosen with certain criteria, and the attributes and results of the studies used are presented.

For example, in a systematic review of studies examining the impact of interventions on sedentary behavior and physical activity through the implementation of standing desks in the school environment, it was found that the strategy of introducing standing desks decreases the length of time schoolchildren sit and has the potential to improve the health status of young people.

10. Case studies

A case study is a research method that can be both quantitative and qualitative, used to address in depth the multiple facets of an event or phenomenon in their real-life context. It is used extensively in the social sciences and in medicine. Case studies can be:

• Intrinsic case study : when you want to learn about a unique phenomenon.
• Instrumental Case Study – Use a particular case to better understand an event or phenomenon more broadly.
• Collective case study : involves the study of multiple cases simultaneously or sequentially, in an attempt to understand and explain a particular issue.

For example, a case of neonatal appendicitis was studied by a group of health professionals in a children’s hospital in Brazil. This would be an instrumental case study where the characteristics of the mother and the baby, their symptoms and the medical procedure to solve the problem are presented.

11. Surveys and questionnaires

Surveys and questionnaires are research methods that can be both quantitative and qualitative, depending on whether numerical or descriptive data are generated, respectively. They are used as instruments to obtain information from individual perspectives in a large group of people. Extensive planning, time and effort are required for its application.

In the medical area, there are three main types of survey: epidemiological surveys, surveys on attitudes towards a health service or intervention, and questionnaires that assess knowledge about a particular topic.

For example, a study in Austria investigated the relationship between attachment style and Internet addiction through questionnaires sent online, distributed by Web-based platforms such as Facebook, and discussion forums.

12. Exploratory sequential method

The exploratory sequential method is a mixed research method where qualitative and quantitative strategies are combined. In a first phase, the researcher explores through the collection and analysis of qualitative data. Then, a tool is designed to obtain quantitative data.

For example, in a study where researchers conduct qualitative interviews with a certain number of people with diabetes, and then develop a classification table that will be applied in another larger study group.

13. Explanatory sequential method

The explanatory sequential method is a mixed research method that combines quantitative and qualitative methods.

The sequential explanatory method has two phases, a first where quantitative data are collected, followed by a phase that seeks to explain qualitatively. Ultimately, the two phases are connected at the interpretation stage to explain the quantitative and qualitative findings.

For example, a study classifies risk behaviors in traffic among young people between the ages of 18 and 25 through a questionnaire. With the quantitative data from the questionnaire, personal interviews are carried out with a selected group of participants to seek to understand the reason for these risky behaviors.

14. Parallel mixed method

The mixed parallel method simultaneously applies a quantitative method and a qualitative method, in order to finally confront the conclusions of the research.

For example, in a study it was reviewed how the communication style of doctors affects the intention to perform a mammogram on a group of women, through a questionnaire and recording of the consultation between the health professional and the patient.

15. Desk method

The desktop research method can be quantitative or qualitative, depending on the data being sought. It can be carried out through consultation of official or personal documents, in libraries, newspaper archives or through the Internet.

For example, to make the biography of Simón Bolívar, his biographer or historian depends on the documents he wrote or received: letters, diaries, proclamations. You can also turn to literature that was written inspired by the character.

It may interest you:

• Types of research
• Research techniques
• Quantitative and qualitative research
• Natural Sciences and Social Sciences