Research techniques are the resources that allow the data and/or information to be obtained in an organized and consistent manner for the search for knowledge.
The techniques used in an investigation must be supported and justified on a theoretical basis. For example, in research on the growth of children over a period of time, forms of physical measurement that reflect growth, such as measures of height and weight, should be used, not the estimation of their parents of how much the children have grown.
There are universal research techniques that can be applied to any area of knowledge. Others, on the other hand, are specific to a field. Below are different techniques that can be used in documentary, field and scientific research.
1. Bibliographic search
Bibliographic search is the collection of information on a given topic. The purpose is to know what has been written about the subject of our interest so that we avoid repetitions, compare the previous information available and discover gaps. Literature search is undoubtedly the main technique in most research areas.
For the bibliographic research process, it is necessary to have informative material such as books, popular magazines or scientific research and websites. You can also count on other types of documents such as videos, footage and audios. These documents can be located in physical and virtual libraries, as well as in hemerographic archives.
When conducting the bibliographic search, we can consider two types of sources:
- The primary sources: These are the writings of an author or authors on a research, which provides first-hand data, i.e. periodicals, books and reference works.
- The secondary sources: these are documents prepared from primary sources, such as a translation, an anthology or a catalog of publications. Dictionaries, encyclopedias and databases are also considered secondary sources.
Tokens are blank or scratched half-sheet cards that were traditionally used by researchers because of their ease of handling. Today they can be replaced by computer files from any word processor using electronic media.
We can identify two types of chips:
- Reference sheets: these are those that contain the identification data of a publication, such as the bibliographic file (includes data on books or any other non-periodical publication) and the hemerographic file (contains information on articles consulted in various periodicals, such as now magazines, the press, reviews, documents, interviews, presentations).
- worksheets: they contain summaries of the readings we have analysed, textual quotations, observations, comments and reflections on the sources of information we have consulted.
The survey is a field research technique where information is obtained directly from the subject of study. In the survey, questions are formulated that are written down and applied to a group of people. The questions are prepared beforehand by the research team, with a rating system that will allow respondents’ answers to be measured.
The most well-known polls are the opinion polls that are carried out before an election in a country to investigate the tendency of the different candidates.
The interview is a field research technique where questions are asked to a subject to obtain the information that will be analyzed. Interviews are generally one-on-one, but can be applied to small groups.
The interviewer acts as a research instrument in extracting qualitative data from a study subject, which is why it is widely used in the social sciences.
One of the advantages of the interview is that it can be applied to learn about past events or to inquire into private situations of the interviewee. For example, in a study on adolescent video game addiction, the interview would be an ideal technique to investigate the reasons for this phenomenon.
You may be interested to see the interview types.
Observation as a research technique is intentional perception with a specific objective. It is selective because it has a purpose within the area where it is applied. For example, astronomers observe the sky with the purpose of finding a new object or space phenomenon.
While making the observation it is necessary to interpret what we perceive, in the context of the area of knowledge involved. For example, if an astronomer observes a strange object in the sky, he must interpret it based on the possible options he has within the area of astronomy, whether it is an asteroid, a star, or a planet.
The observation process has the following steps:
- Perception of the object: recognize the presence of the object, for example, the biologist who observes through the optical microscope a dark spot in a cell.
- Interpretation of the object: the researcher must recognize the perceived object. Thus, the biologist can interpret the dark spot in the cell as an organelle, as a dust particle on the preparation, or as an intracellular parasite.
- Description of the object: with the specific language of the research area in which the observation takes place, objectively. For example, the biologist will describe the dark spot as a circularly shaped structure with a diameter of 1 micrometer adjacent to the nucleus of the cell, etc.
In every observation there is an object that is perceived in certain circumstances by a subject or observer. The circumstances of the observation are the environment of the object and the subject. The observer can make use of means of observation, such as the photographic machine and the thermometer. All this is inserted into a body of knowledge, which will contribute to providing the appropriate explanation.
Scientific observation has a public nature, that is to say, the results of the observation must be reproducible by other specialists under similar conditions. However, there are situations that cannot be repeated such as an earthquake, the explosion of a star or a social uprising.
The experiment is the scientific research technique where the conditions affecting an object are manipulated, to then observe and interpret the result of the manipulation. For example, if you want to determine the effect of light on plant growth, the experiment will be to place some plants in an area with light and other plants in the dark.
In the experiment, the factors surrounding the object are controlled artificially, either directly, as when a stimulus is applied to the object, or indirectly, when the environment surrounding the object is altered . In the case of plants that are placed in the dark, the growth conditions of the plant, which is the object of research, are indirectly altered.
The changes or alterations that the researcher makes in an experiment are based on prior knowledge and the assumptions or hypotheses that he seeks to test. In this way, if the hypothesis is that magnesium favors the exercise of athletes, the experiment will consist of somehow measuring the physical activity of two groups of athletes, one control without magnesium, and the other experimental group with a certain amount of magnesium intake.
7. Mental experiments
The mental experiment is the scientific research technique where models are built to explain a phenomenon, such as atomic models, or situations are simulated using a computer.
Computer simulations are a viable, fast, and inexpensive way to conduct experiments that seek to apply theories that have already been determined through real experiments. They have application to applied sciences and technology.
However, thought experiments are no substitute for reality. For example, epidemiological predictions of the spread of a disease show a possible scenario and serve to take preventive measures.
8. Random sampling
Random sampling is the drawing of a small subset from an initial set. For example, if you want to study the physical conditions of students at a university, a group of students from that university, from different faculties and characteristics, are randomly selected.
The purpose of random sampling is to ensure that in the selected sample there is no predilection for a certain trait and that the results of the study can be approximated to the general characteristics of the population.
You may also be interested in seeing Population and sample.
9. Animal models
Animal models are used in many researches in the field of biology. They serve to study complex cellular and biochemical processes and to evaluate the efficacy and safety of potential therapeutic agents. These results can then be applied to humans.
Among the most used animals we have mice, rats, rabbits, pigs, zebra fish and rabbits. Another advantage of some animal models is that they can be genetically modified, by deleting or inserting genes, so that the effect of that gene can be studied.
The researcher must evaluate the advantages and disadvantages of each model according to the experimental objectives. For example, wound repair research in the area of dermatology uses mice and rats as animal models. On the other hand, rabbits are used in cholesterol metabolism research.
10. Cell cultures
Cell cultures are a research technique where cells are grown in a liquid or solid medium. The cell culture technique must be adapted to the type of cell, using the appropriate micronutrients, temperature and growth factors for their development.
It is applied in microbiology to study the presence of bacteria and their characteristics, as well as to determine their development in the presence of antibiotics. Also in studies of molecular biology, physiology, biochemistry, among others, when you want to address the behavior of a certain type of cell.
11. Genomic sequencing
Genome sequencing techniques are based on identifying each DNA base one by one, like someone spelling the words written in a book. This technique is widely used in genetic research.
Knowing the sequence of a DNA makes it possible to determine mutations that explain a disease, the sequence of the genome of individuals, the relationship between genes and the possible treatments based on genetics.
12. PCR: polymerase chain reaction
The polymerase chain reaction or PCR (polymerase chain reaction) is a technique that revolutionized the way to detect small amounts of DNA in biological samples. It is based on duplicating the DNA chains over and over using an enzyme, the polymerase, until there is a sufficient amount that can be measured.
PCR has several applications, from detecting minimal amounts of viruses to detecting the presence of DNA in fossil samples.
You may be interested to see:
Cázares H., L., Christen, M., Jaramillo L., E., Villasenyor R., L., Zamudio R., LE (1999) Current documentary research techniques, Editorial Trillas. Mexico
Grada A, Mervis, J., Falanga, V. (2018) Research techniques made simple: animal models of wound healing. J. of Investigative Dermatology 138: 2095-2105
Maya Esther (2208) Research methods and techniques. National Autonomous University of Mexico. Mexico