Research methods are the tools that researchers use to obtain and analyze data . These include sampling, questionnaires, interviews, case studies, experimental method, trials, and focus groups. What are the types of research methods?

The choice of the research method is predetermined by the problem to be solved and by the data that can be obtained. Thus, we have quantitative, qualitative or mixed research methods.

Quantitative research methods

Quantitative research methods are used primarily to compare numerically oriented data . Scientific rigor is based on the reliability and validity of the data.

Numerical data analysis includes:

• basic descriptive statistics,
• inferential statistics (parametric or nonparametric) and
• the multivariate statistic (multiple regression, ANCOVA).

Qualitative research methods

Qualitative research methods help us to understand the meaning of a phenomenon, where words are the data of interest . Scientific rigor in these methods is based on credibility, reliability, transferability, and overall consistency. What are the types of research methods?

Researchers tend to collect data at the site where participants experience the problem or situation under study.

Qualitative data collection procedures

• Qualitative observation : when the researcher takes field notes on the behavior and activities of individuals at the research site.
• Qualitative interview : the researcher conducts face-to-face interviews with participants, telephone interview, or engages in focus groups.
• Qualitative documents : the researcher can consult public documents (newspapers, meeting minutes, official reports) or private documents (personal diaries, letters, emails).
• Digital and audiovisual materials : this data can be photographs, art objects, videotapes, web pages, emails, text messages, social media texts, and any form of sound.

Mixed research methods

Mixed research methods use a combination of quantitative and qualitative methods . It involves the collection of both quantitative and qualitative data in response to the research question or hypothesis. What are the types of research methods?

Mixed research methods are applied to research problems with multiple perspectives, such as in the areas of social sciences, education and health.

Types of research methods

Within the quantitative, qualitative and mixed methods, different approaches are presented to obtain the data. Here are the different types of research methods.

1. Meta-analysis

Meta-analysis is a quantitative method that analyzes the results of a group of individual quantitative studies to produce a better estimate of the benefits or disadvantages of an intervention. It is a form of secondary analysis since the data to be analyzed have already been obtained by other researchers and have already been published.

To be valid, all the studies involved must have similar characteristics such as the study population, the type of intervention, and the comparison and measurements performed. For example, Aalbers et al. Conducted a meta-analysis of 2867 papers where music therapy was used for the treatment of depression, finding a short-term beneficial effect. What are the types of research methods?

2. Randomized controlled trial method

The randomized controlled trial method consists of selecting a group of individuals and randomly separating them into an experimental group and a control group. The experimental group receives a treatment and the results are compared with the control group. This method is used mainly in the health area, to measure the effectiveness of a medicine or drug.

For example Donald T. Sawyer and Frederic J. Noel wanted to study the effect of an audience on learning abilities. They selected 64 students between 15 and 18 years old and divided them into groups at random, where they were in the presence or not of an audience. The results were that the presence or absence of an audience did not affect the learning process. What are the types of research methods?

3. Experimental method

In the experimental method, the researcher manipulates one or more variables to determine how this manipulation affects the result, while keeping the other variables constant. For example, if we want to show the effect of temperature on plant growth, we place several plants of the same species and age at different temperatures, but keep the light, water, soil and air conditions the same.

4. Ethnographic method

This method seeks to capture, interpret and explain how a group, organization or community lives and is widely used in the field of anthropology. This study tries to answer questions related to specific groups of people.

The intention of the ethnographic method is to obtain a general picture of the study subject with an emphasis on presenting the daily experiences of individuals. What are the types of research methods?

5. Meta synthesis

The qualitative meta synthesis is the qualitative version of the meta-analysis. It requires the inclusion of all reports of qualitative methods published on a given topic.

6. Focus groups

Focus groups are collective conversations or group interviews , where the interaction stimulates ideas that probably would not arise in individual interviews. For example, in an investigation on the effect of drugs, a focus group of adolescents with drug addiction problems who share their experiences can provide more data than the individual interview.

7. Mixed convergent method

The convergent method addresses qualitative and quantitative data separately, then compares the results and confirms the findings. What are the types of research methods?

The analysis of the data in the convergent method has three phases:

1. First, the analysis of the qualitative database by assigning a code and grouping them into topics.
2. Second, the analysis of the quantitative database in terms of statistical results.
3. Third, the integration of the two databases joining the results found.

8. Explanatory sequential mixed method

The sequential explanatory method comprises data collection in two phases:

• In the first phase, the researcher collects quantitative data and analyzes it;
• In the second phase, the quantitative results are used to plan the qualitative phase.

The quantitative results inform the types of participants to be selected for the qualitative phase and the types of questions to be presented to the participants. The intent of this method is to use qualitative data to help explain the initial quantitative results in detail. What are the types of research methods?

9. Mixed sequential exploratory method

The exploratory sequential method is a mixed method that consists of:

• an initial phase of qualitative data collection;
• a next phase of quantitative data collection.

The purpose of the exploratory sequential method is to explore with an initial sample in such a way that the quantitative phase can be designed according to the needs of the individuals to be studied.

10. Embedded mixed method

The embedded or nested method occurs when qualitative data is obtained within a quantitative method, or vice versa. For example, in a study of a drug in a clinical trial, a participant satisfaction questionnaire is applied.

11. Survey and questionnaire

Research surveys and questionnaires provide the quantitative description of trends, attitudes, and opinions of a population. The surveys answer three questions: What are the types of research methods?

• Descriptive questions: What percentage of professionals find a job after completing their studies?
• Questions about the relationships between variables: Is there a relationship between college grades and a professional’s monthly income?
• Questions about predictive relationships between variables over time: Do the best paid professionals out of college achieve better positions after ten years of continuous work?

12. Case study

The case study can be seen as a hybrid of qualitative and quantitative method. It is about presenting the characteristics and findings of a particular individual. In medicine, a case study is, for example, presenting the signs and symptoms of a person with a rare disease.

For this, a simple case of a certain situation, individual or interest group is selected in its context. The information is obtained through a series of data collection techniques such as observation, interview and document analysis. What are the types of research methods?

13. Desk or library method

The desk, cabinet, or library research method can be either quantitative or qualitative. It is applied in cases where data collection is not possible, appropriate or ethical, so it is preferable to carry out the investigation by reviewing and analyzing previously obtained data. Currently this can be done through the Internet and literature review. This type of method also serves to prepare experimental research and / or complement it.

14. Interview

Interviews are one of the most widely used qualitative data collection methods. They may be:

• Semi-structured : they are exploratory interviews, flexible, where the interviewer can interact with the interviewee.
• Structured : the same questions are applied to the participants in the same order and the same range of answers are presented.
• Individualized : they are designed to obtain deeper information on a group of individuals who share characteristics and experiences. What are the types of research methods?

15. Observational research method

In the observational method, the researcher does not intervene in the situation, he only observes. Three types of studies are described:

• Cohort studies : a group of people is selected, some parameters are measured and after a while the presence of the condition of interest is determined. It is used to determine the incidence and natural history of a condition. For example, you take a group of people and you want to determine what characteristics are associated with diabetes. The recruits are in good health, and after a certain number of years those with diabetes are checked.
• Cross-sectional studies : they are used to determine the prevalence of a disease, that is, the number of people affected by the disease at a time.
• Case-control studies : people with a certain condition (case) are compared with people who do not have that condition (control). It is used to determine the importance of some predictive agent. For example, a case-control study was done in 236 people with autism and 345 people without autism (control) to determine the sequence of the HOXB1 gene . Mutations in this gene were found not to be associated with autism. What are the types of research methods?