Before you decide to carry out your research by applying an experimental research design. You need to understand what is experimental research and where the experimental research design is applicable.
Experimental research is defined as a systematic and scientific approach in which the researcher manipulates one variable and measures and controls changes in other variables.
Experimental research designs are applicable in all such studies where the researcher wants to establish a cause and effect relationship among the variables.
The experimental research design may be carried out in a wide variety of settings as well, meaning it’s not limited to the laboratory setting alone but can be conducted in the field, laboratory and natural settings.
How to develop experimental research design
Once you understand what the experimental research design means, you will start questioning how to go about in developing such a design, so here’s brief discussion of the steps involved in this research process.
Since experimental research is a scientific and systematic approach of study it must follow the scientific steps to conduct research. It should be noted that there are several types of experimental study designs the difference between experimental and non-experimental research design is in their methodology.
Steps in experimental study design
The first step in any research however, remains identification of the research problem . For this the researcher needs to conduct a thorough literature review.
The literature review helps the researcher to establish the fact that the question is really good and worth conducting a research on.
Having identified the research problem and reviewing the available literature, the researcher (i.e. you) will now formulate a testable research hypothesis which would include an independent variable and a dependent variable in order to establish the cause and effect relationship.
The research hypothesis is what would be equivalent to an educated and informed guess on your part. At the end of your experiment the hypothesis is either accepted or rejected when tested against a null hypothesis, whichever way it goes, the hypothesis helps explain why things happen the way they do.
Designing the experiment
Once the research hypothesis is established, you the researcher then move forward to the stage of designing or devising the experiment in order to test the hypothesis.
Imagine yourself as a driver in a completely unfamiliar neighborhood searching for a friend’s address. What would you need, clear and precise directions and guidelines for sure isn’t it? Otherwise you would get lost and not arrive at the friend’s address at all. Same is true for the experimental researcher who wishes to conduct an experiment in order to deduct results.
The researcher needs clear and precise guidelines regarding the experiment. So what does he/she do? The answer to this is that the researcher plans, devices or designs his/her experiment to arrive at the result.
Thus decided, the planning and designing stage is where the researcher decides on the intricacies or in simple words the details of the experiment. It involves deciding on the experimental and control groups, what the population is going to be, (when choosing the population you need to take care that the population is large enough so that you can claim the results to be representative for the whole population yet small enough to be practical), the sample size, the sampling frame, units of analysis, the sampling method to be chosen etc.
As a rule of thumb the experimental and control groups are equivalent and the units of analysis assigned to the groups are chosen at random this allows each unit a chance to be equally selected, reduces the probability of experimental errors and helps to establish the validity of the experimental results. The type of experiment you choose would depend on your time, budget and other ethical factors involved.
So, now you have a clear and precise road map, what do you do next? You (the researcher) are now at the stage of actually conducting the experiment.
In this stage, the researcher exposes the experimental (test) group to the treatment, i.e the independent variable, the control group on the other hand does not receive the treatment rather it serves as the baseline for evaluating the behaviour (dependent variable) of the experimental or test group.
In order to better understand the experimental method let’s take a look at this example. Suppose a collage professor wants to establish that class attendance and the professors lectures have an impact on how well students perform in exams and results in higher test scores than those who do not have regular attendance. What would the professor do? The professor would randomly divide the pupils into two comparable groups, expose the pupils in the experimental group to the treatment (in this case the class attendance and lectures) while the pupils in the control group would be excused from attendance. The professor would then make the pupils of both groups take the same exam and compare the results. If the final results show a difference in the performance levels of the experimental group from those of the control group, the professor would be able to establish a cause and effect relationship between the two variables and be able to deduce that class attendance and the professors lectures do in fact effect the pupils performance levels and results in higher test scores.
- Key, J. P. (1997). “Module R13 Experimental Research and Design”. Research Design in Occupational Education. Oklahoma State University. https://www.okstate.edu/ag/agedcm4h/academic/aged5980a/5980/newpage2.htm
- Mitchell, O. “Experimental Research Design”. https://onlinelibrary.wiley.com/doi/pdf/10.1002/9781118519639.wbecpx113
- Mitchell, O. (Oct 2015). “Experimental Research Design”. Willey Online Library.