The Experimental Method
IISA Assessment, Consultancy & Research Centre helps you determine whether a causal relationship exists between two or more variables. For that, we assist researchers find ways to directly manipulate the cause (independent variables), the procedure to randomize individual composition at different levels of independent variables, and measure their responses (the expected effects). We help focusing, so that researchers have a high degree of control towards the presentation of treatment, determining when the treatment is to be imposed, and in what form; including who receives it, and when and how to measure the effects.
The level of stringency of this control help researchers rule out alternative or rival explanations to the results observed. To ensure the control happens correctly, the research needs to be done under laboratory conditions or attempted to be sterile from natural settings of everyday life. However, this experimental method can also be used in the real world or in the field.
Conducting experiments in field is more difficult, mainly because of the complexity of integrating the parts of the experimental method preconditions. As well as the treated subjects tend to leave the arena of experiment, those randomly assigned to the control group are even prone to decide to be imposed by out of design treatments of the experiment. We will assist you if you are forced to apply such field experimental method.
The alternation of the experimental method is the quasi-experimental method. This method is a research strategy since in reality it is not possible to fully assign participants randomly according to rank conditions on the independent variables. Therefore, two most often used procedures in quasi-experimental are time-series design and nonequivalent comparison group design.
In the first design, the effects on dependent variables are measured several times before and after the independent variables are subjected. For example, in studies of implementation policy of the Law Road Traffic (UULJR) No 14, 1993, the number of related traffic violation incidents is recorded on a monthly basis for twelve months before the policy was introduced, and compares to twelve or more months after the implementation. If a significant reduction of the incidents occurs immediately after application of the policy and so the reduction persists, it can be assured that the new policy became the main cause of the observed reduction; by noting that no other events occur and resulting the declining of traffic violation incidents.
While in the second design—nonequivalent comparison group design—a causal relationship is more difficult to be convinced. The explanation is if the treated group is formed not by a random manner (for example, according to the participants’ choices), this often means that the participants come from different preconditions and this affects the results of observations on the dependent variable. For example, selected are the students who have academic problems; they are then allowed to choose to engage or not to engage in after-school tutoring program.
Those who decide to sign up are likely those who also (1) be more motivated to improve their academic achievement; (2) have parents who are willing to help their children improving their academic achievement; (3) choose not to go straight home after completion of school hours; even (4) have less serious academic problems to be fixed.
These factors may contribute as another cause of the increase or decrease of academic achievement beyond the provision of after-school tutoring program. We have advice and guidance to validate the characteristics of both groups before accepting tutorial.