In today's data-driven world, how to most effectively analyze and interpret data continues to become a critical issue in scientific research, engineering, and business decision-making. As an effective experimental design method, fractional factorial design can help us deeply understand the main factors that affect the results while saving resources. What are the hidden secrets behind this design approach?
A fractional factorial design is an experimental design that reveals the most important features of a system by running it on a subset of a full factorial design. The core of this method is to use the "sparsity principle of effects", that is, in many full factorial design experiments, there are a large number of redundant experimental runs and cannot show new information. Therefore, performing a fractional factorial design can effectively reduce the demand for experimental resources and focus on the most influential factors.
The main effects of many experiments can often be revealed with a small number of runs, making fractional factorial designs widely used in a variety of fields.
The concept of fractional factorial design was first proposed by British statistician David Finney in 1945, and his research expanded the work of Ronald Fisher on full factorial experiments. Originally developed for agricultural applications, this design method has since been adopted in a wide range of fields including engineering, science, and business.
For example, when an engineer wants to increase the filtration rate of a chemical process and reduce the use of formaldehyde, he might consider four factors: temperature (A), pressure (B), formaldehyde concentration (C), and stirring rate (D). By using a full factorial design with 24 runs, the experiment can then be conducted based on a half-fractional design, which effectively reduces the number of runs and extracts the main influencing factors.
The fractional factorial design makes each main effect redundant with the three-factor interaction, which provides simplified results for further analysis.
When designing fractional factor experiments, researchers must consider interactions between factors because they can be confounded and not clearly distinguished. Higher-order interactions are often considered negligible, making it feasible to focus on the main effects. However, the planning of such a design requires specific considerations, especially when more than two factors are involved, which can have a significant impact on the labor requirements of the experiment.
In summary, fractional factorial design is a powerful experimental design tool with far-reaching impact. It allows researchers to discover and analyze important main effects in data with minimal resource effort. However, as design complexity increases, so do confounding effects. This makes people think, in the rapidly changing scientific and business environment, how to balance efficiency and accuracy to achieve the best experimental design results?