A graphical analysis for each effect in the design matrix is obtained by plotting the average response at the (-1) and (1) levels for each column after plotting these averages, the dots are connected to form a line, See Figure 8.12 for the complete graphical analysis, For example the large dot, ….., on Figure 8.12 is a result of averaging all the response values when the factor A column is at a +1,i.e., the average of runs 5 through 8 or