Understanding the Details
Manual Analysis Using MS Excel
While the formulas provide many insights into the 2K factorial design of experiments, the use of MS Excel provides much easier alternative way to calculate the contrasts, effects, estimates, sum of squares and the development of the ANOVA table is shown in Video 6.
MS Excel File 2 shows the manual calculation procedure to find the contrasts, estimates, effects, sum of squares, and ANOVA table for the problem # 6.7 in page 293 from a popular Design and Analysis of Experiments Textbook (Montgomery 2013). The problem or the design consists of four variables affecting a chemical process. Two replications were collected. The MS Excel File 2 shows an easier alternative way to find the contrasts, effects, estimates, sum of squares, and the development of the ANOVA table without plugging the numbers in the formulas, rather a much easier process is applied using the basic MS excel functions, which has been proven to be very useful when a dedicated statistical software is unavailable. Even when a dedicated statistical software is available, over a decade of experience in DOE, the author finds the use of MS excel procedure is very useful in many design and analysis of experiments, including the 2K factorial design of experiments. As the data structure and layout is already there in the MS Excel, as soon as the data collection is completed, the analysis will be generated automatically with a little tweak in the formula. It may even take less time than running analysis in a statistical software.
MS Excel File 2. MS Excel in the manual analysis of a 2k factorial design of experiments Montgomery 8th Ed Solution to Problem # 6.7