Substitution of cobalt driers in wood coatings

Appendix A - Statistical analysis of 26-3 fractional factorial designs.

1 Design and results

Click here to see table with design and results

2 Statistic analysis

General Linear Models
---------------------
Number of dependent variables: 7
Number of categorical factors: 8
Number of quantitative factors: 0

Analysis of Variance for YellowingOne

Source Sum of Squares Df Mean Square F-Ratio P-Value
Model 14871,5 9 1652,39 1015,40 0,0000
Residual 61,8388 38 1,62734
Total (Corr.) 14933,4 47      
 
Type III Sums of Squares
Source Sum of Squares Df Mean Square F-Ratio P-Value
Anti skin 0,259602 1 0,259602 0,16 0,6918
Binder 0,0462521 1 0,0462521 0,03 0,8670
Color 14790,8 1 14790,8 9088,95 0,0000
Drier 28,1515 2 14,0758 8,65 0,0008
Fungicide 0,0910021 1 0,0910021 0,06 0,8143
HALS 2,47975 1 2,47975 1,52 0,2246
Thix binder 49,5524 1 49,5524 30,45 0,0000
UV abs 0,155269 1 0,155269 0,10 0,7591
Residual 61,8388 38 1,62734    
Total (corrected) 14933,4 47      

All F-ratios are based on the residual mean square error.

R-Squared = 99,5859 percent
R-Squared (adjusted for d.f.) = 99,4878 percent
Standard Error of Est. = 1,27567
Mean absolute error = 0,92467
Durbin-Watson statistic = 2,28349

Residual Analysis

  Estimation Validation
N 48  
MSE 1,62734  
MAE 0,92467  
MAPE 7,60461  
ME -5,71765E-15  
MPE -1,41698  

 

Analysis of Variance for Yellowing28

Source Sum of Squares Df Mean Square F-Ratio P-Value
Model 14318,0 9 1590,89 1033,84 0,0000
Residual 58,475 38 1,53881    
Total (Corr.) 14376,5 47      
 
Type III Sums of Squares
Source Sum of Squares Df Mean Square F-Ratio P-Value
Anti skin 0,0229688 1 0,0229688 0,01 0,9034
Binder 0,00016875 1 0,00016875 0,00 0,9917
Color 14242,0 1 14242,0 9255,16 0,0000
Drier 37,1699 2 18,5849 12,08 0,0001
Fungicide 0,188752 1 0,188752 0,12 0,7281
HALS 2,31002 1 2,31002 1,50 0,2280
Thix binder 36,3138 1 36,3138 23,60 0,0000
UV abs 0,00175208 1 0,00175208 0,00 0,9733
Residual 58,475 38 1,53881    
Total (corrected) 14376,5 47      

All F-ratios are based on the residual mean square error.

R-Squared = 99,5933 percent
R-Squared (adjusted for d.f.) = 99,4969 percent
Standard Error of Est. = 1,24049
Mean absolute error = 0,908741
Durbin-Watson statistic = 1,87598

Residual Analysis

  Estimation Validation
N 48  
MSE 1,53881  
MAE 0,908741  
MAPE 6,32946  
ME -5,71765E-15  
MPE -1,25901

 

Analysis of Variance for Tack6

Source Sum of Squares Df Mean Square F-Ratio P-Value
Model 45,3281 9 5,03646 10,39 0,0000
Residual 18,4167 38 0,484649    
Total (Corr.) 63,7448 47      
 
Type III Sums of Squares
Source Sum of Squares Df Mean Square F-Ratio P-Value
Anti skin 3,25521 1 3,25521 6,72 0,0135
Binder 0,130208 1 0,130208 0,27 0,6072
Color 0,046875 1 0,046875 0,10 0,7575
Drier 39,5417 2 19,7708 40,79 0,0000
Fungicide 1,17188 1 1,17188 2,42 0,1282
HALS 1,17188 1 1,17188 2,42 0,1282
Thix binder 0,00520833 1 0,00520833 0,01 0,9180
UV abs 0,00520833 1 0,00520833 0,01 0,9180
Residual 18,4167 38 0,484649    
Total (corrected) 63,7448 47      

All F-ratios are based on the residual mean square error.

R-Squared = 71,1088 percent
R-Squared (adjusted for d.f.) = 64,2661 percent
Standard Error of Est. = 0,696167
Mean absolute error = 0,471354
Durbin-Watson statistic = 1,44214

Residual Analysis

  Estimation Validation
N 48  
MSE 0,484649  
MAE 0,471354  
MAPE 27,0263  
ME 0,0  
MPE -9,77203  

 

Analysis of Variance for Tack24

Source Sum of Squares Df Mean Square F-Ratio P-Value
Model 11,6667 9 1,2963 5,59 0,0001
Residual 8,8125 38 0,231908    
Total (Corr.) 20,4792 47      
 
Type III Sums of Squares
Source Sum of Squares Df Mean Square F-Ratio P-Value
Anti skin 0,1875 1 0,1875 0,81 0,3742
Binder 0,0833333 1 0,0833333 0,36 0,5524
Color 0,0208333 1 0,0208333 0,09 0,7660
Drier 10,2917 2 5,14583 22,19 0,0000
Fungicide 0,1875 1 0,1875 0,81 0,3742
HALS 0,520833 1 0,520833 2,25 0,1422
Thix binder 0,1875 1 0,1875 0,81 0,3742
UV abs 0,1875 1 0,1875 0,81 0,3742
Residual 8,8125 38 0,231908    
Total (corrected) 20,4792 47      

All F-ratios are based on the residual mean square error.

R-Squared = 56,9685 percent
R-Squared (adjusted for d.f.) = 46,7768 percent
Standard Error of Est. = 0,481568
Mean absolute error = 0,365451
Durbin-Watson statistic = 1,91465

Residual Analysis

  Estimation Validation
N 48  
MSE 0,231908  
MAE 0,365451  
MAPE 8,79998  
ME 2,59052E-16  
MPE -1,10805  

 

Analysis of Variance for HardnessOne

Source Sum of Squares Df Mean Square F-Ratio P-Value
Source Sum of Squares Df Mean Square F-Ratio P-Value
Model 133,833 9 14,8704 24,13 0,0000
Residual 23,4167 38 0,616228    
Total (Corr.) 157,25 47      
 
Type III Sums of Squares
Source Sum of Squares Df Mean Square F-Ratio P-Value
Anti skin 0,0 1 0,0 0,00 1,0000
Binder 18,75 1 18,75 30,43 0,0000
Color 0,333333 1 0,333333 0,54 0,4666
Drier 112,5 2 56,25 91,28 0,0000
Fungicide 0,0833333 1 0,0833333 0,14 0,7151
HALS 0,0833333 1 0,0833333 0,14 0,7151
Thix binder 1,33333 1 1,33333 2,16 0,1495
UV abs 0,75 1 0,75 1,22 0,2769
Residual 23,4167 38 0,616228    
Total (corrected) 157,25 47      

All F-ratios are based on the residual mean square error.

R-Squared = 85,1086 percent
R-Squared (adjusted for d.f.) = 81,5817 percent
Standard Error of Est. = 0,785002
Mean absolute error = 0,586806
Durbin-Watson statistic = 2,70544

Residual Analysis

  Estimation Validation
N 48  
MSE 0,616228  
MAE 0,586806  
MAPE 6,17109  
ME 0,0  
MPE -0,591566  

 

Analysis of Variance for Hardness7

Source Sum of Squares Df Mean Square F-Ratio P-Value
Model 919,146 9 102,127 31,47 0,0000
Residual 123,333 38 3,24561    
Total (Corr.) 1042,48 47      
 
Type III Sums of Squares
Source Sum of Squares Df Mean Square F-Ratio P-Value
Anti skin 1,02083 1 1,02083 0,31 0,5782
Binder 63,0208 1 63,0208 19,42 0,0001
Color 2,52083 1 2,52083 0,78 0,3837
Drier 592,667 2 296,333 91,30 0,0000
Fungicide 42,1875 1 42,1875 13,00 0,0009
HALS 105,021 1 105,021 32,36 0,0000
Thix binder 54,1875 1 54,1875 16,70 0,0002
UV abs 58,5208 1 58,5208 18,03 0,0001
Residual 123,333 38 3,24561    
Total (corrected) 1042,48 47      

All F-ratios are based on the residual mean square error.

R-Squared = 88,1692 percent
R-Squared (adjusted for d.f.) = 85,3672 percent
Standard Error of Est. = 1,80156
Mean absolute error = 1,30903
Durbin-Watson statistic = 2,34626

Residual Analysis

  Estimation Validation
N 48  
MSE 3,24561  
MAE 1,30903  
MAPE 10,5103  
ME -7,03141E-16  
MPE -1,12406  

 

Analysis of Variance for Drying time

Source Sum of Squares Df Mean Square F-Ratio P-Value
Model 141,904 9 15,7671 14,10 0,0000
Residual 41,3728 37 1,11818    
Total (Corr.) 183,277 46      
 
Type III Sums of Squares
Source Sum of Squares Df Mean Square F-Ratio P-Value
Anti skin 10,6892 1 10,6892 9,56 0,0038
Binder 2,0086 1 2,0086 1,80 0,1883
Color 1,28211 1 1,28211 1,15 0,2912
Drier 118,325 2 59,1626 52,91 0,0000
Fungicid 7,36865 1 7,36865 6,59 0,0144
HALS 1,3163 1 1,3163 1,18 0,2850
Thix binder 1,62506 1 1,62506 1,45 0,2357
UV abs 0,0224921 1 0,0224921 0,02 0,8880
Residual 41,3728 37 1,11818    
Total (corrected) 183,277 46      

All F-ratios are based on the residual mean square error.

R-Squared = 77,426 percent
R-Squared (adjusted for d.f.) = 71,9351 percent
Standard Error of Est. = 1,05744
Mean absolute error = 0,714632
Durbin-Watson statistic = 1,76075

Residual Analysis

  Estimation Validation
N            47  
MSE 1,11818  
MAE 0,714632  
MAPE 14,817  
ME 0,0  
MPE -3,2546  

 

The StatAdvisor

--------------------

This pane summarizes the results of fitting 7 general linear statistical model relating 7 dependent variables to 8 predictive factors. Since the P-value in the first ANOVA table for YellowingOne is less than 0.01, there is a statistically significant relationship between YellowingOne and the predictor variables at the 99% confidence level.

The R-Squared statistic indicates that the model as fitted explains 77,426% of the variability in YellowingOne. The adjusted R-squared statistic, which is more suitable for comparing models with different numbers of independent variables, is 71,9351%. The standard error of the estimate shows the standard deviation of the residuals to be 1,05744. This value can be used to construct prediction limits for new observations by selecting the Reports option from the text menu. The mean absolute error (MAE) of 0,92467 is the average value of the residuals. The Durbin-Watson (DW) statistic tests the residuals to determine if there is any significant correlation based on the order in which they occur in your data file. Since the DW value is greater than 1.4, there is probably not any serious autocorrelation in the residuals.

The output also summarizes the performance of the model in fitting the data, and in predicting any values withheld from the fitting process. It displays:

   (1) the mean squared error (MSE)
   (2) the mean absolute error (MAE)
   (3) the mean absolute percentage error (MAPE)
   (4) the mean error (ME)
   (5) the mean percentage error (MPE)

Each of the statistics is based on the residuals. The first three statistics measure the magnitude of the errors. A better model will give a smaller value. The last two statistics measure bias. A better model will give a value close to 0.0.

Below is a graphical presentation of the significant factors

Diagram: Significant factors

Diagram: Significant factors

Diagram: Significant factors

Diagram: Significant factors

 



Version 1.0 August 2006, © Danish Environmental Protection Agency