To define experimental research design, at first we must define the term experiment and its elements. The term experiment is familiar to us but comprehensive to define. Experimenter (person who conduct experiment), independent variables, dependent variables, control variables and hypothesis are general components of experiments.experiment is generally any activities where experimenter manipulate some variables by controlling other factors or variables that affect the dependent variables in close or partially control environment. In the field of social science fully control environment are rarely exist.
Experimental research is the investigation where researchers try to observe the effect of manipulating variables on dependent variable(s) on controlled environment. It is the quantitative research focuses on measure and compare of dependent variables with control group or with information before intervention is made. Research contain hypothesis set by researcher, controlled environment (fully or partially controlled)and the variables (manipulating variable and affected variable as set by hypothesis). One of the goals of experimental research is to find out the effects on the dependent variable by experimental or manipulated variables.
Types of Experimental Research
Experimental research may be random experiment or semi-experimental based on method of assigning to people. In random experimental research, researcher selected the sample randomly and intervention is done and researcher observed the result of that intervention to draw the conclusion. Randomized Control trial is the best example of random experimental research method. In Semi-experimental research, researcher cannot able to control all the control variables. They only try to reduce the impact of control variables. These experimental research design are practice in social science research where there is impossibility of control some variables and investigator normally try to minimize the impact of it.
Some of experimental research are performed in the laboratory. Normally, in pure science field these types of research is conducted. These research types are called laboratory research. In social science most of the experimental research are perform in society where controlling variables are less possible to control. When researchers conduct the experimental research in the field than it is commonly called field experimental research.
Basic Designing Experimental Research
There are a couple of steps for conducting the experimental research design. Researcher at first realized the research problem and set the objectives of conducting research. These are the basis of all research design. After setting the objectives of experiment researcher develop the hypothesis for investigation. It is necessary for identification of manipulating variables, controlling variables, the degree of control on research environment and measuring variables. After that the researcher define the variable use in research. Researchers define manipulating variables, controlling variable and measurable variable. Researcher selects the sampling procedure after defining the variables. Selection of sample(s) are determined by the types of experimental research, purpose and research environment. Design of experiment and identifying the sampling procedure are the parallel work that must be considered for designing experimental research. Research must consider either pre-experimental research, quasi-experimental and true experimental research according to the nature of intervention, controlling environment and so on. Researchers consider single group (without controlling group) in pre-experimental research design, consider at least two groups but select in non random basis or researcher select at least two groups selecting randomly for true experimental research design. Researcher selects the tools of data collection, measurement for drawing the conclusion from findings. In last phases, possible formats of report writing and presentation of research findings.