Most often, when carrying out certain scientific studies, a hypothetical method is used, in which an assumption is made about the cause that caused certain consequences. Then this assumption is verified empirically so that it can be called a statement. All this requires certain material and time costs, since in order to obtain a reliable result, it is necessary to conduct several experiments with the same initial data. To reduce the number of parallel studies and options for combining certain factors will help carefully executed design of the experiment.
This can be achieved by choosing such test conditions under which the results of statistical processing of the obtained values of the output parameter will allow us to draw adequate conclusions about the process under study. The design of the experiment involves finding a specific mathematical model that will most closely describe the process under study. The choice of the plan is carried out as a result of the analysis of information matrices. It is worth noting that the progress of the statistical analysis of the obtained experimental data and its effectiveness directly depend on the plan. Choosing a plan, you must:
- determine the criterion for planning the experiment;
- to develop a model that will most closely describe the structure and nature of the relationship in the investigated object or process;
- to compare the resulting model with existing, with standard plans. Based on the analysis, choose the optimal plan.
The theory of experimental design is widely used in various fields of science and technology. Moreover, turning to a specific topic, it is necessary to take into account certain nuances and features of this scientific field in order to correctly prepare and conduct empirical studies, the purpose of which in most cases is to find optimal conditions under which the parameters of the object under study (system response) have extreme values, then have reach their maximum or minimum value.
The design of the experiment allows you to minimize time, especially in the case of the influence of several different factors on the final result of the experiment, and the consumption of material resources. Each experience is able to bring the researcher the maximum possible amount of information. This can only be achieved if the preparation and implementation of the practical part is correct.
The planning and organization of the experiment involves
- the choice of the number of variable factors. Here it is necessary to choose the most significant variables that affect the response function. You can identify them in the course of preliminary exploratory experiments, a review of literary sources;
- determination of the number of levels of each variable factor. In this case, either a qualitative or quantitative value of the level is determined, which, moreover, can be fixed or random. There are no specific recommendations for finding an interval for a change in factors; therefore, in this paragraph, you should turn to literary sources to determine possible intervals for a change in a factor, or use your personal experience;
- determination of the required number of measurements of the value of the response function. This amount depends on the established restrictions, the required accuracy and the possible influence of one factor on another.
Thus, the design of an experiment is a powerful tool in the hands of every scientist, which can significantly reduce the time required for research and increase its accuracy to the required level. Each researcher should not only know this method, but also successfully apply it in practice in order to achieve the goal with minimum cost.