The techniques used in an investigation must be supported and justified on a theoretical basis. For example, in an investigation of children’s growth over a certain period of time, one should resort to forms of physical measurement that reflect growth, such as height and weight measurements, not their parents’ estimate of how much their children have grown.
They consist of 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.
It is the collection of information on a certain topic. The purpose is to know what is written on the subject of our interest so that we avoid repetitions, compare the previous information available and discover gaps. The literature search is undoubtedly the main technique in most areas of research.
The bibliographical research phase must have informative material such as books, popular magazines or scientific research and websites. You can also have other types of documents such as videos, footage and audio. These documents can be located in physical and virtual libraries, as well as in hemerographic archives.
When performing the bibliographic search, we can consider two types of sources:
- Primary sources: are the writings of an author or authors on research, which provides first-hand data, that is, periodicals, books and reference works.
- Secondary sources: are those 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.
They are white or lined half-page cards that researchers traditionally used because of their easy handling. Today they can be replaced by computer files from any word processor using electronic means.
We can identify two types of tokens:
- Reference files: are those that contain the identification data of a publication, such as the bibliographic file (includes the data of the books or any other non-periodical publication) and the hemerographic file (contains information on articles consulted in various periodical publications, such as magazines, the press, reviews, documents, interviews, presentations).
- Worksheets: they contain summaries of the readings that we have analysed, quotes, observations, comments and reflections on the sources of information that we have consulted.
It is a field research technique where information is obtained directly from the study subject. The survey asks questions that are noted down and applied to a group of people. The questions are previously prepared by the research team, with a rating system that will allow the measurement of the responses of the respondents.
The best known polls are the opinion polls that are carried out prior to an election in a country to find out the tendency of the different candidates.
It is a field research technique where a subject is asked questions to obtain the information to be analyzed. Interviews are usually individual, but can be applied to small groups.
The interviewer acts as a research instrument by 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 find out about past events or investigate the 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.
Observation as a research technique is intentional perception with a specific objective. It is selective because it has a purpose within the area in which it is applied. For example, astronomers observe the sky in order to find a new object or space phenomenon.
While observing, what we perceive must be interpreted 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 that he has within the field of astronomy, whether it is an asteroid, a comet or a planet.
The observation process has the following steps:
- Object perception: recognize the presence of the object, for example, the biologist who observes through the light microscope a dark spot on a cell.
- Interpretation of the object: the researcher must recognize the perceived object. Thus, the biologist can interpret the dark spot on the cell as an organelle, as a dust particle on the preparation, or as an intracellular parasite.
- Description of the object: with the language of the research area in which the observation is carried out, objectively. For example, the biologist will describe the dark spot as a circular shaped structure with a diameter of 1 micrometer adjacent to the nucleus of the cell, among others.
It is the scientific research technique where the conditions that affect an object are manipulated, and then the result of the manipulation is observed and interpreted. For example, if you want to determine the effect of light on plant growth, the experiment will be to place some plants in a light area and other plants in the dark.
In the experiment, the factors that surround the object are artificially controlled, either directly, such 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.
It is the scientific research technique where models are put together that explain a phenomenon, such as atomic models, or situations are simulated using a computer.
Computer simulations are a viable, fast and cheap way to carry out experiments that seek to apply theories that have already been determined through real experiments. They have application in applied sciences and technology.
Thought experiments are not substitutes for reality. For example, epidemiological predictions of the spread of a disease show a possible scenario and serve to take preventive measures.
It is the extraction of a small subset from an initial set. For example, if you want to study the physical conditions of university students, 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 approximate the general characteristics of the population.
They are used in many investigations in the area of biology. They serve to study complex cellular and biochemical processes and to evaluate the efficacy and safety of potential therapeutic agents. Those results can then be applied to humans.
Among the most used animals we have mice, rats, rabbits, pigs, zebrafish and guinea pigs. Another advantage of some animal models is that they can be genetically modified, canceling or inserting genes, with which the effect of said gene can be studied.
It is a research technique where cells are grown in a liquid or solid medium. The cell culture technique must be adapted to the cell type, using the appropriate micronutrients, temperature and growth factors for cell 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.
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 allows us to determine mutations that explain a disease, the genome sequence of individuals, the relationship between genes and possible treatments based on genetics.
PCR: polymerase chain reaction
The polymerase chain reaction or PCR (for its acronym in English polymerase chain reaction) is a technique that revolutionized the way of detecting minimal amounts of DNA in biological samples. It is based on duplicating DNA strands over and over again using an enzyme, polymerase, until there is a sufficient quantity that can be measured.
PCR has various applications, from detecting minimal amounts of viruses to detecting the presence of DNA in fossil samples.