Common Mistakes Made in Some Literatures When Performing Orthogonal Experiments and Solutions

OBJECTIVE To improve the quality and utility of orthogonal experiments. METHODS The orthogonal experiments in published literatures were reviewed. RESULTS The common mistakes made in some literatures and outcomes were: orthogonal design or orthogonal table without blank column, resulting in inflating the random effect; baselessly ignoring the interactions, resulting in confounding bias; wrong results of analysis of variance (ANOVA) because of manual calculation; the selection of optimal process without considering cost-effectiveness, incurring cost increase of manufacturing. CONCLUSION Blank column of orthogonal table should be reserved for error estimated; the interactions could be ignored only when their existence are denied in relevant experiments and literatures; the data of orthogonal experiments should be analyzed using statistical software to make sure the accuracy of the results, and the cost-effectiveness should be considered in the selection of optimal process.