344 
Fishery Bulletin 106(4) 
Table 4 
Results of logistic modeling for mortality in Chionoecetes bairdi (Tanner crab). A backward stepwise approach was used to 
determine the most parsimonious model for mortality, and an alpha value of 0.15 was required to remove a variable from the full 
model. 
Parameter 
Estimate 
t-ratio 
P-value 
Full model 
constant 
-2.346 
-1.226 
0.220 
gender 
-0.114 
-0.383 
0.701 
shell condition 
-0.274 
-0.805 
0.421 
size 
0.005 
0.244 
0.807 
reflex impairment 
1.316 
5.364 
<0.001 
injury score 
1.029 
4.743 
<0.001 
Most parsimonious model 
Parameter 
constant 
-2.710 
-8.957 
<0.001 
reflex impairment 
1.353 
5.731 
<0.001 
injury score 
1.044 
4.767 
<0.001 
Prediction matrix for the most parsimonious model 
No. dead predicted 
No. alive predicted 
Actual total 
Dead 
51.4 
21.6 
73 
Alive 
21.6 
155.4 
177 
Total predicted 
73 
177 
250 
Correct (%) 
70.4 
87.8 
False (%) 
29.6 
12.2 
Total correct (%) 
82.7 
Table 5 
Results of logistic modeling for mortality in Chionoecetes opilio (snow crab). A backward stepwise approach was used to determine 
the most parsimonious model for mortality, and an alpha value of 0.15 was required to remove a variable from the full model. 
Parameter 
Estimate 
t-ratio 
P-value 
Full model 
constant 
-2.716 
-1.933 
0.053 
gender 
0.333 
0.815 
0.415 
shell condition 
-0.089 
-0.292 
0.770 
size 
-0.016 
-1.128 
0.259 
reflex impairment 
1.416 
8.240 
<0.001 
injury score 
-0.102 
-0.384 
0.701 
Most parsimonious model 
Parameter 
constant 
-3.913 
-10.529 
<0.001 
reflex impairment 
1.349 
9.622 
<0.001 
Prediction matrix for the most parsimonious model 
No. dead predicted 
No. alive predicted 
Actual total 
Dead 
78 
18 
96 
Alive 
18 
285 
303 
Total predicted 
96 
303 
399 
Correct (%) 
81.2 
94.1 
False (%) 
18.8 
5.9 
Total correct (%) 
91.0 
