Experimental Method: Definition and Meaning

Experimentation has a long history in psychology and education. When psychology first emerged as an infant discipline in the 1900s, it patterned its research methodologies on the established paradigms of the physical sciences, which had depended on experimentation for millennia to develop principles and rules. Following that, the dependence on experimental procedures was enhanced by behavioral approaches to psychology and education that predominated during the first part of the twentieth century. Thus, during the last 40 years, the use of experimentation in educational technology has been affected by advancements in theory and research techniques within its parent disciplines.

What is an Experiment?

The cause-and-effect link between two known variables is established and quantified using the experimental research method. This is not to argue that experimental work cannot be done in the field or outside a lab. A chemist, for instance, may operate in a lab, but an astronomer will have to sit in his observatory and watch natural and uncontrollable occurrences as they happen. Experimentation requires more work, takes time, and is frequently difficult to create. Therefore, the issue of why one would go to such bother emerges. Why not just watch or investigate the phenomenon? Any non-experimental study's primary flaw is its inability to identify the causes and effects.

Experimental Research Design

According to a proverb, need is the mother of innovation. A curious mind is constantly looking for novel ideas. The experimental mindset necessary for experimental research is created by the need, recognizing the lack, and seeking to change the circumstance. In an experimental design, there are two subject groups. One is the control group, which is not the subject of any experiments, and the other is the experimental group, which is the subject of experiments. In the case of the experimental group, one variable is added at a time to see if its presence affects this group's condition.

The fundamental principle of experimental design is to modify one factor simultaneously while leaving the others unaltered. In order to prove a cause-and-effect relationship, every experimental design must satisfy what is known as the law of the single variable. Therefore, a sufficient level of control is a crucial component of the experimental research process. The following components are provided for an experimental design−

The technical and organizational aspects of an experiment are called its experimental design. These aspects include the number of experimental groups, how the groups are formed, the types and numbers of independent variables, whether repeated observations are taken, etc. These properties can be very different, and when combined, they result in a wide range of potential experimental designs. Specialists have categorized four different designs as experimental designs, and they are as follows−

Before-After or Pre-test- Post-test Experimental Design

Typically, this is referred to as classical experimental design. It reflects the so-called four-cell architecture and is more dependable. Here, all the groups are chosen, watched, and measured prior to the experiment. There is one dependent variable and one independent variable, the therapy. The experimental group and the control group are randomly allocated to the subjects. After that, both groups' dependent variables are assessed. Only the experimental group participants are given the therapy after the pre-test. The dependent variable is assessed for each group, and comparisons are made. It is time for the post-test. One drawback of this design is that it cannot be guaranteed to remain free from the impact of other causes.

After-only or Pre-test only Experimental Design

The study is conducted in this design under social circumstances, which are not within the control of the physical or natural circumstances. Two topic groups are selected that are comparable across the board. The first is referred to as the experimental group and the second as the control group. The experimental group is subjected to the experiment using the planned methodology. Both groups are observed, and the results of the experimental method are measured after the time specified. The differences between the results are used to identify changes that the experiment's variable manipulation caused in the experimental group.

Quasi or Ex-Post Facto Experimental Design

The phrase "quasi-experiment" refers to circumstances where individuals cannot be randomly assigned to experimental groups, but the independent variable can still be changed. We can no longer talk of experimentation when such manipulation is impossible, i.e., when the stimulus is beyond the researcher's control; instead, we have an analysis of co-variation. Nevertheless, there are instances of research that, although lacking the two characteristics of experimentation (i.e., randomization and manipulation), involves a very similar design to an experiment. Ex post facto describes these types of designs.

Special design (Mixed Design)

Multifactor amongst topics design, often known as mixed design, is a unique type of design. One factor is between when one element is inside, and another is within. Computer software and a statistical consultant are required for this concept. This type of mixed designing is employed when the experimenter thinks that order effects are not a concern, requires power, and wishes to generalise the results to situations in real life where participants are likely to get more than two levels of the treatment.

Randomization in Experiments

The confounding variables must be partially removed. Consequently, there is room for incorrect result interpretation. By using randomization, a method of assigning people to the experimental and control groups, this can be avoided. Any reasonable technique can be used to complete the task, including flipping a coin, utilizing a table of random numbers, the lottery method, and more.

This will guarantee that each person has an equal chance of being assigned to the experimental or control group. It also alludes to the capacity to generalize study results. The representativeness of the sample and the reactive arrangements are two aspects of external validity that can impact how research findings are generalized.

Randomly assigning people to experimental and control groups will guarantee group equality and the study's internal validity. It might just represent the chosen sample and only some of the population. Expensive rejection rates and high costs could make it difficult to choose a representative sample. The reactive arrangements will come next. A study's findings should be applied to a real-life scenario and a wide population. It is challenging to do this and can cause the test subjects to respond negatively. For example, a pre-test might influence how people react to the experimental stimuli. By choosing post-test alone, this impact may be prevented.


Experimentation is a social research method that works well for specific problems, group analysis, dynamics of interpersonal contact, and other phenomena that occur in a constrained amount of time, location, and participants. The very foundation of scientific thinking is the cause-and-effect relationship. In social science, there are two types of experiments: laboratory and field. The experiment is conducted in a controlled environment, whereas a real-world setting is employed in the latter. Impact studies, judgment studies, and observational studies are the categories into which laboratory experiments may be divided.

Updated on: 05-Apr-2023


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