Sociology

Experimental Research Design

Experimental research design is a scientific method that is used to test cause-and-effect relationships between variables. In an experimental design, the researcher manipulates one or more independent variables to observe the effect on a dependent variable. This is done by creating two or more groups, one that is exposed to experimental manipulation and another that is not, which allows the researcher to compare the differences in the dependent variable between the groups.

Experimental research design involves a set of procedures that are designed to control extraneous variables and increase the internal validity of the study. This includes random assignment of participants to groups, the use of control groups, and the manipulation of the independent variable. By using these techniques, researchers can make strong causal inferences about the effects of the independent variable on the dependent variable.

Experimental research design is commonly used in fields such as psychology, biology, and physics, where it is important to establish causal relationships between variables. It is considered the gold standard in research design because it provides the most rigorous method for testing hypotheses and making causal inferences.

The concept of experimental design in sociological research refers to systematic study of human relations by making the observations under conditions of control. In the words of Jahoda and Cook, ‘an experiment may be considered as a way of organizing the collection of evidence so as to permit one to make inference about the tenability of a hypothesis. According to Chapin, “experiment is simple observation under controlled conditions. When observation alone fails to disclose the factors that operate in a given problem, it is necessary for the scientist to resort to experiment.”

Types of Experimental Design

Experimental designs are structured plans that guide the collection of data and the testing of hypotheses in a scientific study. There are several types of experimental designs, including:

1. Pre-experimental design: 

This design involves a single group of participants and does not have a control group. This design is the weakest form of experimental design and is generally not considered as reliable as other designs.

2. True experimental design: 

This design involves randomly assigning participants to experimental and control groups and manipulating an independent variable to observe its effect on a dependent variable. This design is considered the most reliable form of experimental design.

3. Quasi-experimental design: 

This design involves a non-random assignment of participants to groups, but still includes manipulation of an independent variable. This design is used when random assignment is not feasible or ethical.

Thus, experimental designs are important in scientific research as they provide a structured plan for collecting data and testing hypotheses. There are several types of experimental designs, including pre-experimental design, true experimental design, quasi-experimental design, factorial design, repeated measures design, single-subject design, cross-sectional design, and longitudinal design. Each type of design has its own advantages and disadvantages and is appropriate for different types of research questions. Choosing the appropriate experimental design is essential for ensuring the reliability and validity of the study's results.

ADVANTAGES OF EXPERIMENTAL RESEARCH

1. It provides researchers with a high level of control:

By being able to isolate specific variables, it becomes possible to determine if a potential outcome is viable. Each variable can be controlled on its own or in different combinations to study what possible outcomes are available for a product, theory, or idea as well. This provides a tremendous advantage in an ability to find accurate results.

2. There is no limit to the subject matter or industry involved:

Experimental research is not limited to a specific industry or type of idea. It can be used in a wide variety of situations. Teachers might use experimental research to determine if a new method of teaching or a new curriculum is better than an older system. Pharmaceutical companies use experimental research to determine the viability of a new product.

3. Experimental research provides conclusions that are specific:

Because experimental research provides such a high level of control, it can produce results that are specific and relevant with consistency. It is possible to determine success or failure, making it possible to understand the validity of a product, theory, or idea in a much shorter amount of time compared to other verification methods. You know the outcome of the research because you bring the variable to its conclusion.

4. The results of experimental research can be duplicated:

Experimental research is straightforward, basic form of research that allows for its duplication when the same variables are controlled by others. This helps to promote the validity of a concept for products, ideas, and theories. This allows anyone to be able to check and verify published results, which often allows for better results to be achieved, because the exact steps can produce the exact results.

5. Natural settings can be replicated with faster speeds:

When conducting research within a laboratory environment, it becomes possible to replicate conditions that could take a long time so that the variables can be tested appropriately. This allows researchers to have a greater control of the extraneous variables which may exist as well, limiting the unpredictability of nature as each variable is being carefully studied.

6. Experimental research allows cause and effect to be determined:

The manipulation of variables allows for researchers to be able to look at various cause-and-effect relationships that a product, theory, or idea can produce. It is a process which allows researchers to dig deeper into what is possible, showing how the various variable relationships can provide specific benefits. In return, a greater understanding of the specifics within the research can be understood, even if an understanding of why that relationship is present isn’t presented to the researcher.

7. It can be combined with other research methods:

This allows experimental research to be able to provide the scientific rigor that may be needed for the results to stand on their own. It provides the possibility of determining what may be best for a specific demographic or population while also offering a better transference than anecdotal research can typically provide.

The advantages and disadvantages of experimental research show that it is a useful system to use, but it must be tightly controlled in order to be beneficial. It produces results that can be replicated, but it can also be easily influenced by internal or external influences that may alter the outcomes being achieved. By taking these key points into account, it will become possible to see if this research process is appropriate for your next product, theory, or idea.

LIMITATION/DISADVANTAGES OF EXPERIMENTAL RESEARCH

1. Results are highly subjective due to the possibility of human error:

Because experimental research requires specific levels of variable control, it is at a high risk of experiencing human error at some point during the research. Any error, whether it is systemic or random, can reveal information about the other variables and that would eliminate the validity of the experiment and research being conducted.

2. Experimental research can create situations that are not realistic:

The variables of a product, theory, or idea are under such tight controls that the data being produced can be corrupted or inaccurate, but still seem like it is authentic. This can work in two negative ways for the researcher. First, the variables can be controlled in such a way that it skews the data toward a favorable or desired result. Secondly, the data can be corrupted to seem like it is positive, but because the real-life environment is so different from the controlled environment, the positive results could never be achieved outside of the experimental research.

3. It is a time-consuming process:

For it to be done properly, experimental research must isolate each variable and conduct testing on it. Then combinations of variables must also be considered. This process can be lengthy and require a large amount of financial and personnel resources. Those costs may never be offset by consumer sales if the product or idea never makes it to market. If what is being tested is a theory, it can lead to a false sense of validity that may change how others approach their own research.

4. There may be ethical or practical problems with variable control:

It might seem like a good idea to test new pharmaceuticals on animals before humans to see if they will work, but what happens if the animal dies because of the experimental research? Or what about human trials that fail and cause injury or death? Experimental research might be effective, but sometimes the approach has ethical or practical complications that cannot be ignored. Sometimes there are variables that cannot be manipulated as it should be so that results can be obtained.

5. Experimental research does not provide an actual explanation:

Experimental research is an opportunity to answer a Yes or No question. It will either show you that it will work or it will not work as intended. One could argue that partial results could be achieved, but that would still fit into the “No” category because the desired results were not fully achieved. The answer is nice to have, but there is no explanation as to how you got to that answer. Experimental research is unable to answer the question of “Why” when looking at outcomes.

6. Extraneous variables cannot always be controlled:

Although laboratory settings can control extraneous variables, natural environments provide certain challenges. Some studies need to be completed in a natural setting to be accurate. It may not always be possible to control the extraneous variables because of the unpredictability of Mother Nature. Even if the variables are controlled, the outcome may ensure internal validity, but do so at the expense of external validity. Either way, applying the results to the general population can be quite challenging in either scenario.

7. Participants can be influenced by their current situation:

Human error isn’t just confined to the researchers. Participants in an experimental research study can also be influenced by extraneous variables. There could be something in the environment, such an allergy that creates a distraction. In a conversation with a researcher, there may be a physical attraction that changes the responses of the participant. Even internal triggers, such as a fear of enclosed spaces, could influence the results that are obtained. It is also very common for participants to “go along” with what they think a researcher wants to see instead of providing an honest response.

8. Manipulating variables isn’t necessarily an objective standpoint:

For research to be effective, it must be objective. Being able to manipulate variables reduces that objectivity. Although there are benefits to observing the consequences of such manipulation, those benefits may not provide realistic results that can be used in the future. Taking a sample is reflective of that sample and the results may not translate over to the general population.

9. Human responses in experimental research can be difficult to measure:

There are many pressures that can be placed on people, from political to personal, and everything in-between. Different life experiences can cause people to react to the same situation in different ways. Not only does this mean that groups may not be comparable in experimental research, but it also makes it difficult to measure the human responses that are obtained or observed.

While experimental research design has several advantages, researchers must also consider its limitations. These include artificiality, ethical concerns, limited external validity, time and resource limitations, inability to control all variables, Hawthorne effect, and demand characteristics. By considering these limitations, researchers can design studies that maximize the strengths of experimental research design while minimizing its weaknesses.

Features of experimental research design

Experimental research design is a type of research design used in scientific studies that involves the manipulation of one or more independent variables to observe the effects on a dependent variable. Here are some key features of experimental research design:

1. Independent and dependent variables: 

The experimental design must have one or more independent variables that are manipulated and one dependent variable that is measured. The independent variable is the variable that the researcher controls or manipulates, while the dependent variable is the variable that is being measured.

2. Random assignment: 

Participants in the study must be randomly assigned to groups to ensure that any differences between groups are not due to pre-existing differences between participants.

3. Control group: 

Experimental research design typically includes a control group that does not receive the manipulation of the independent variable. This allows the researcher to compare the effects of the independent variable on the dependent variable between the experimental group and the control group.

4. Manipulation of variables: 

The experimental design involves manipulating the independent variable to observe its effect on the dependent variable. This manipulation is done in a standardized and systematic way to ensure that the results are reliable and valid.

5. Pre-test and post-test measures: 

Experimental research design typically involves collecting data before and after the manipulation of the independent variable. This allows the researcher to compare the differences between the two groups before and after the manipulation of the independent variable.

6. Replication: 

Experimental research design can be replicated under different conditions to ensure that the results are consistent and generalizable.

7. Randomization: 

The experimental design must be randomized to ensure that any differences between groups are not due to chance.

8. Hypothesis testing: 

Experimental research design is well-suited for hypothesis testing because it involves systematic manipulation of variables and observation of their effects on the dependent variable.

Experimental research design on the other hand, involves the manipulation of one or more independent variables to observe the effects on a dependent variable. It includes random assignment, a control group, manipulation of variables, pre-test and post-test measures, replication, randomization, and hypothesis testing. These features ensure that the results of the study are reliable, valid, and generalizable.

Experimental research design with suitable examples

Experimental research design is a research method that involves manipulating one or more independent variables to observe their effect on a dependent variable. This design is widely used in scientific research to establish cause-and-effect relationships between variables. Here are a few examples of experimental research design:

1. Drug efficacy study: 

In a drug efficacy study, participants are randomly assigned to either a treatment group that receives the drug or a control group that receives a placebo. The independent variable is the drug, and the dependent variable is the improvement in the medical condition. By comparing the improvement in the treatment group and control group, the researchers can establish whether the drug is effective in treating the condition.

2. Educational intervention study: 

In an educational intervention study, students are randomly assigned to either an experimental group that receives a new teaching method or a control group that receives the standard teaching method. The independent variable is the new teaching method, and the dependent variable is the improvement in academic performance. By comparing the improvement in the experimental and control groups, the researchers can determine whether the new teaching method is effective in improving academic performance.

3. Memory experiment: 

In a memory experiment, participants are randomly assigned to either an experimental group that uses a mnemonic device or a control group that does not use a mnemonic device. The independent variable is the use of the mnemonic device, and the dependent variable is the accuracy of memory recall. By comparing the accuracy of memory recall in the experimental and control groups, the researchers can determine whether the mnemonic device is effective in improving memory recall.

4. Nutrition study: 

In a nutrition study, participants are randomly assigned to either an experimental group that follows a specific diet or a control group that follows a standard diet. The independent variable is the specific diet, and the dependent variable is the change in body weight. By comparing the change in body weight in the experimental and control groups, the researchers can determine whether the specific diet is effective in reducing body weight.

5. Environmental study: 

In an environmental study, participants are randomly assigned to either an experimental group that is exposed to a specific environmental condition (e.g., air pollution, noise pollution) or a control group that is not exposed to the environmental condition. The independent variable is the environmental condition, and the dependent variable is the change in health (e.g., respiratory problems, hearing loss). By comparing the change in health in the experimental and control groups, the researchers can determine whether the environmental condition is harmful to human health.

6. Marketing study: 

In a marketing study, participants are randomly assigned to either an experimental group that is exposed to a new advertising campaign or a control group that is exposed to the standard advertising campaign. The independent variable is the advertising campaign, and the dependent variable is the change in product sales. By comparing the change in product sales in the experimental and control groups, the researchers can determine whether the new advertising campaign is effective in increasing sales.

7. Sports performance study: 

In a sports performance study, athletes are randomly assigned to either an experimental group that receives a new training method or a control group that receives the standard training method. The independent variable is the new training method, and the dependent variable is the change in performance (e.g., speed, accuracy). By comparing the change in performance in the experimental and control groups, the researchers can determine whether the new training method is effective in improving performance.

8. Technology study: 

In a technology study, participants are randomly assigned to either an experimental group that uses a new software application or a control group that uses the standard software application. The independent variable is the new software application, and the dependent variable is the change in user satisfaction. By comparing the change in user satisfaction in the experimental and control groups, the researchers can determine whether the new software application is more user-friendly than the standard software application.

9. Crime prevention study: 

In a crime prevention study, participants are randomly assigned to either an experimental group that receives a specific crime prevention program or a control group that does not receive the program. The independent variable is the crime prevention program, and the dependent variable is the change in crime rates (e.g., number of burglaries, number of robberies). By comparing the change in crime rates in the experimental and control groups, the researchers can determine whether the crime prevention program is effective in reducing crime.

10. Social psychology study: 

In a social psychology study, participants are randomly assigned to either an experimental group that is exposed to a specific social intervention (e.g., empathy training, bias reduction) or a control group that does not receive the intervention. The independent variable is the social intervention, and the dependent variable is the change in attitudes or behaviour (e.g., reduced prejudice, increased helping behaviour). By comparing the change in attitudes or behaviour in the experimental and control groups, the researchers can determine whether the social intervention is effective in promoting positive social outcomes.

11. Education study: 

In an education study, participants are randomly assigned to either an experimental group that receives a specific education program or a control group that does not receive the program. The independent variable is the education program, and the dependent variable is the change in academic achievement (e.g., grades, test scores). By comparing the change in academic achievement in the experimental and control groups, the researchers can determine whether the education program is effective in improving academic performance.

12. Healthcare study: 

In a healthcare study, participants are randomly assigned to either an experimental group that receives a specific healthcare intervention (e.g., patient education, disease management) or a control group that receives standard care. The independent variable is the healthcare intervention, and the dependent variable is the change in health outcomes (e.g., reduced symptoms, improved quality of life). By comparing the change in health outcomes in the experimental and control groups, the researchers can determine whether the healthcare intervention is effective in promoting positive health outcomes.

These examples demonstrate how experimental research design can be used to answer a variety of research questions across different fields of study. By manipulating one or more independent variables and observing their effects on a dependent variable, researchers can establish cause-and-effect relationships and make informed decisions based on the results of the study.