Components of Experimental Research Design
The experimental research design can be described as one of the most robust quantitative research approaches. The design provides an opportunity to make empirical inductions and should therefore be planned and implemented as meticulously as possible. Creswell (2014) describes some of the components of the experimental research design as well as the principles of conducting experimental research. The components described by Creswell include the participants, instruments and procedures, experimental variables, data analysis, results interpretation and the threats to experimental validity. These components have immense impact on the conduct of the experimental research and have to be reviewed before as well as during the experimental conduct. The paper henceforth discusses various components of the experimental research design. The main objective of the discussion is to create an understanding of the experimental procedures and the key components of the design.
Components of an Experimental Research Design
Rao and Shah (2002), opine that the objective of any experimental research design would be to establish a cause – effect relationship where the same is assumed to be in existence. According to Rao and Shah, the experimental research design has components which include the participants; the elements or factors; the experimental setting; instruments and methods; experimental procedures; the statistical analysis methods and the experimenter. While the components mentioned by Rao and Shah are almost similar to those mentioned by Creswell (2014), the consideration of the experimenter as part of the experimental components raises questions regarding the upholding of experimental validity. No experiment can be conducted without the experimenter. It is therefore necessary that the experimental components should be inclusive of the experimenter. Furthermore, the experimental procedure takes into consideration every aspect of the design through to the implementation stage.
The second component of the experimental research design according to Creswell is that of the participants. The participants in this regard are described as the subjects from whom the information is to be gathered. The participants can be selected either randomly or through convenience sampling and also placed into groups depending on their capabilities. Participants have to be competent at providing the desired information without placing the study at risk. While creating the study report, the experimenter must explain in details the strategy sued for allocating the participants into different groups. While discussing the components of the experimental design, Kandada (2013) purports that the participants chosen must be a strong representative of the entire population sample. This implies that all the characteristics of the entire population target must be represented in the sample selected. The choice of the study units must also be such that the units chosen fit the study objective perfectly. This is in line with the requirements laid down by Creswell. The choice of the participants should be such that the experimental procedures and the instruments to be used are capable of fitting the participant objectives.
In planning the experimental procedure and the experimental instruments, the experimenter has to ask themselves what their objective is in conducting the experiment. The instrument used must be capable of helping the experimenter to achieve their goals with respect to the instructions to be followed. The procedures used must also give way for the experimenter to establish relationships that they consider beneficial to the research project. According to Knight (2010), the research instruments and methods vary immensely, and the choice of the right methodological approaches distinguishes successful experiments from unsuccessful ones. The choice of methods forms the bulk of the methodology chapter and it is required that the procedures and the instruments be explained in details to enable experimental replication. Creswell (2014) asserts that the description of the experimental instruments should include methods of instrument development as well as the scales to be used in data representation. Measures of validity and proof of the same should also be provided. The experimental procedure is to be discussed to include the type of procedure, whether quasi- experimental, true experiment or pre-experimental procedures. The design discussion should also have an indication of the comparison strategy to be used.
The application of different experimental research instruments impact the research findings differently. For instance, the greatest characteristic that should be possessed by any experimental research process and results is that of validity. The best measure of the experimental validity is the results obtained through the data analysis stage. The experimental analysis strategy depends on the variables that have been selected for the process. The variables have to be categorized into the dependent and independent variables during the experimental procedure description. In this way, the data analysis stage of experimental research can take into consideration all the factors pertaining to the experiment. In Creswell’s (2014) argument, various factors, both internal and external can affect the validity of the experimental research design. Some of these factors include: the internal threats to validity such as the experimental procedures; the choice of participants and the treatments. The external sources of threat to experimental validity include; the sample characteristics, experimental setting and the timing of the experiment. From these descriptions, it is clear that the choices made by the experimenter in terms of selecting procedures and implementing the experimental design have great impacts on the validity of the experiment. It is thus crucial for the experimenter to consider and to review the available experimental research design options and to consider ethical dispositions while at it as White and Sabarwal (2014) opine.
Creswell, J.W. (2014). Research design: Qualitative, quantitative and mixed methods approaches 3rd Ed. Sage Publications: Thousand Oaks. www.socsci.uci.edu/~castellj/198research/fall/Week%209/Readings/Ch08-PPT-QuantitativeMethods.pdf
Rao, M. and Shah, S. (2002). Experimentation: A research methodology. Research methods in Agriculture. Retrieved from www.public.asu.edu/~kroel/www500/EXPERIMENTATION%20Fri.pdf
Kandada , A. (2013). Components of an experimental study design. Retrieved from stats.libretexts.org/Core/Experimental_Design/Analysis_of_Variance/Components_of_an_experimental_study_design
Knight, K.L. (2010). Study/ experimental/ research design: Much more than statistics. Journal of Athletic Training, 45(1): 98- 100. Retrieved from www.ncbi.nlm.nih.gov/pmc/articles/PMC2808761/pdf/i1062-6050-45-1-98.pdf
White, H. and Sabarwal, S. (2014). Quasi experimental design and methods. Methodological Brief No. 8, UNICEF. Retrieved from www.unicef-irc.org/publications/pdf/brief_8_quasi-experimental%20design_eng.pdf