NON-EXPERIMENTAL RESEARCH: DESIGNS, CHARACTERISTICS, EXAMPLES - SCIENCE - 2025

The experimental investigation is one in which not controlled or manipulated variables of the study. To develop the research, the authors observe the phenomena to be studied in their natural environment, obtaining the data directly to analyze them later.

The difference between non-experimental and experimental research is that in the latter, variables are manipulated and the study is carried out in controlled settings. Thus, for example, gravity is experienced by intentionally dropping a stone from various heights.

On the other hand, in non-experimental research, researchers go, if necessary, to the place where the phenomenon to be studied occurs. For example, to find out about the drinking habits of young people, surveys are conducted or directly observed how they do it, but they are not offered a drink.

This type of research is very common in fields such as psychology, measurement of unemployment rates, consumer studies or opinion polls. In general, these are pre-existing events, developed under their own internal laws or rules.

Non-experimental research designs

Compared with what happens with experimental research, in non-experimental research the variables studied are not deliberately manipulated. The way to proceed is to observe the phenomena to be analyzed as they appear in their natural context.

In this way, there are no stimuli or conditions for the subjects being studied. These are in their natural environment, without being transferred to any laboratory or controlled environment.

The existing variables are of two different types. The former are the independent calls, while the so-called dependent ones are a direct consequence of the previous ones.

In this type of research, the relationship of causes and effects is investigated to draw valid conclusions.

Since situations are not created expressly to investigate them, it can be said that non-experimental designs study existing situations developed under their own internal rules.

In fact, another name that is given is that of ex post facto investigations; that is, on accomplished facts.

Differences with experimental designs

The main difference between the two types of research is that in experimental designs there is manipulation of the variables by the researcher. Once the desired conditions are created, studies measure their effects.

On the other hand, in non-experimental investigations this manipulation does not exist, but the data is collected directly in the environment in which the events occur.

It cannot be said that one method is better than the other. Each one is equally valid depending on what is going to be studied and / or the perspective that the researcher wants to give to her work.

Due to its own characteristics, if the research is experimental, it will be much easier to repeat it to ensure the results.

However, the control of the environment makes some variables that may appear spontaneously more difficult to measure. It is just the opposite of what happens with non-experimental designs.

characteristics

As already indicated above, the first characteristic of this type of research is that there is no manipulation of the variables studied.

Usually these are phenomena that have already occurred and are analyzed afterwards. Apart from this characteristic, other peculiarities present in these designs can be pointed out:

- Non-experimental research is widely used when, for ethical reasons (such as giving drinks to young people), there is no option to carry out controlled experiments.

- Groups are not formed to study them, but these are already pre-existing in their natural environments.

-Data is collected directly, and then analyzed and interpreted. There is no direct intervention on the phenomenon.

- It is very common for non-experimental designs to be used in applied research, since they study events as they occur naturally.

- Given the characteristics presented, this type of research is not valid for establishing unequivocal causal relationships.

Types

Cross-sectional or transectional design

This type of non-experimental research design is used to observe and record data at a specific time and, by its very nature, unique. In this way, the analysis that is carried out is focused on the effects of a phenomenon that occurs at a particular moment.

As an example, we can mention the study of the consequences of an earthquake on the houses in a city or the rates of school failure in a given year. You can also take more than one variable, making the study a more complex one.

The cross-sectional design allows covering diverse groups of individuals, objects or phenomena. When developing them, they can be divided into two different groups:

Descriptive

The objective is to investigate those incidents and their values, in which one or more variables appear. Once the data is obtained, it is simply a description of it.

Causal

These designs try to establish the relationships between several variables that occur at a given time. These variables are not described one by one, but rather an attempt is made to explain how they are related.

Longitudinal design

Contrary to what happens with the previous design, in the longitudinal one the researchers intend to analyze the changes that certain variables undergo over time. It is also possible to investigate how the relationships between these variables evolve during this period.

To achieve this objective it is necessary to collect data at different points in time. There are three types within this design:

Trending

They study the changes that occur in some general population.

Group evolution

The subjects studied are smaller groups or subgroups.

Panel

Similar to the previous ones but with specific groups that are measured at all times. These investigations are useful to analyze the individual changes together with the group ones, allowing to know which element has produced the changes in question.

Examples

In general, these designs are made for the study of events that have already happened and, therefore, it is impossible for the variables to be controlled. They are very frequent in statistical fields of all kinds, both to measure the incidence of some factors and for opinion studies.

Effects of alcohol

A classic example of nonexperimental research is studies on the effects of alcohol on the human body. As it is unethical to give the subjects studied to drink, these designs are used to obtain results.

The way to achieve this would be to go to places where alcohol is regularly consumed. There the degree that this substance reaches in the blood is measured (or data can be taken from the police or some hospital). With this information, the different individual reactions will be compared, drawing conclusions about it.

Opinion polls

Any survey that attempts to measure the opinion of a certain group on a topic is carried out using non-experimental designs. For example, electoral polls are very common in most countries.

School performance

It would only be necessary to collect the statistics of the results of the schoolchildren offered by the schools themselves. If, in addition, you want to complete the study, you can search for information on the socioeconomic level of the students.

Analyzing each data and relating them to each other, a study is obtained about how the socioeconomic level of families affects the performance of schoolchildren.

References

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5. ReadingCraze.com. Research Design: Experimental and Nonexperimental Research. Retrieved from readingcraze.com
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7. Wikipedia. Research design. Retrieved from en.wikipedia.org