The three main types of scientific experiments are experimental, quasi-experimental, and observational (non-experimental).
Experimental, or randomized control, is the highest level of scientific experimentation. As the name indicates, there is the greatest amount of control. In this form of scientific experiment, at least two groups are used. Each group is made up of subjects who are as similar as feasible in terms of age, gender, and other factors. Humans, animals, and the environment are all possible subjects. The subjects are assigned to one of two groups, as the name implies. The following description will utilize two groups for clarity, but experiments can have more than two groups.
Complete randomization can be accomplished in a variety of ways. You can, for example, use a random number generator that you can find for free on the internet. After you’ve gotten your results, put every other number in the column in the control group. The remainder will be placed in the experimental group [1].
The dependent variable is the experiment’s major focus; it is what is being investigated in the experiment. The independent variable is what has changed in the experiment. This is known as manipulation of the independent variable because it is only modified in the experimental group. The independent variable foes not change in the control group.
Quasi-experimental is the second type of scientific experiment. Its goal is to prove that an independent and dependent variable have a cause-and-effect connection. A quasi-experiment, unlike a true experiment, does not rely on random assignment. Subjects are instead divided into groups depending on non-random factors. In circumstances where true experiments are not possible due to ethical or practical considerations, quasi-experimental design is a useful technique.
For example: You learn that a number of the clinic’s psychotherapists have chosen to try out the new therapy, while others who serve comparable patients have chosen to continue with the old one. These pre-existing groups can be used to compare the symptom development of individuals who received the new therapy vs those who received the standard course of treatment. Although the groups were not assigned at random, if any systematic differences between them are correctly accounted for, you can be pretty confident that any differences must be due to the therapy and not other confounding variables [2].
Non-experimental research is study in which no independent variable is manipulated. Non-experimental researchers just measure variables as they naturally occur rather then influencing an independent variable (in the la bor real world). Non-experimental research is preffered in a variety of situations [3], including when:
- Rather than a statistical relationship between two variables, the study question or hypothesis is focused on a single variable.
- The research topic is about a statistical link between variables that isn’t causal.
- The research question is about a causal link, but for practical or ethical reasons, the independent variable cannot be changed, and participants cannot be randomly assigned to conditions or orders of conditions.
- The study question is wide and exploratory, or it asks what it’s like to go through a particular experience.
VRLab Academy offers students and instructors many interactive experiments on general natural sciences, especially biology, physics, and chemistry. It includes all three types of experiemtns that was explained above. In this way, students have the opportunity to do all kinds of experiments and expand their knowledge.
Take a look at all experiments at VRLab Academy and enhance your teaching power with us.
References
[1]. ‘Scientific Experiment: Definition & Examples’, 2015.
[2]. Lauren Thomas, ‘Quasi-Experimental Design: Definiton, Types and Examples’, 2020.
[3]. S. Milgram, ‘Obedience to authority: An experimental view’, 1974.