Experimentation is one of the common methods used in quantitative research. Premised on the positivist philosophy, an experiment is essentially conducted to investigate causal relationships between variables (Bryman, 2008). Indeed, this is one of the major strengths of experimental research compared to other types of studies -- it not only describes association between variables, but also explains causation between variables (Kothari, 2004). This essay describes the various components of an experimental method plan. The paper also explains threats to validity as well as nuances involved in interpreting results from an empirical study.An experimental design has four major components: participants, materials, procedures, and measures (Creswell, 2014). Participants denote the subjects from which the required data will be obtained. The participants section should describe the process of selecting and assigning the participants. This involves explaining whether random or non-random procedures will be used to select participants, whether the participants will be randomly assigned to groups (true experimental design) or not randomly assigned (quasi-experimental design), and how systematic bias will be controlled (Creswell, 2014). Though random sampling is important for avoiding or minimizing bias, at times the researcher may be compelled to use non-random techniques such as convenience sampling due to the nature of the target population (Martin & Bridgmon, 2012). The participants section should also describe the number of participants selected and the number assigned to...
An appropriate sample size should be used to ensure the sample is sufficiently representative of the target population (Kothari, 2004).
Measures denote the variables or outcomes that will be measured (Thomas, 2009). The researcher should clearly identify the independent variables (variables not influenced by other variables) and dependent variables (variables influenced by the independent variables). The treatment variable must be one of the independent variables (Creswell, 2014). Once variables are defined, the researcher must describe the instruments used to measure the variables. This involves explaining the development of the instruments as well as their items, scales, validity, and reliability (Creswell, 2014). This is a particularly important step as lack of instrument validity and reliability may undermine the eventual findings (Thomas, 2009). The researcher must also describe the materials administered for the experimental treatment.
The component of procedures involves describing the actual experimentation process. First, the researcher identifies the nature of experiment to be conducted -- true experiment, quasi experiment, pre-experimental design, or single-subject design (Creswell, 2014). As mentioned previously, a true experiment involves randomization of subjects into groups, while a quasi-experiment involves non-randomization. In a pre-experimental design, only a single group is studied -- there is no control group. A single-subject design entails studying a single subject over time. The chosen…
