Results of the 2011 cod ageing exchange using randomly selected samples from the second, third and fourth quarters of the 2010 DFO commercial and 2010 and 2011 DFO spring survey samples. (A) Agreement plot, showing the ages attained by each reader. A small amount of noise was added to the data to improve visibility of overlapping data points. (B) Age-frequency table, showing each reader's ages. Numbers in the shaded boxes indicate agreement between the two ages. Numbers above this diagonal indicate fish which were given higher ages by the Canadian age reader; those below the shaded boxes were given higher ages by the U.S. age reader. Total age frequencies are given by age for both readers. (C) Results summary, indicating results for the U.S. reader relative to each age for the Canadian reader.

Species: Cod Test Type: 2011 U.S./Canada Ageing Exchange
Sample Source: 2010 DFO Commercial Samples (Q2-Q4) and 2010 & 2011 DFO Spring Survey (NED201001 & NED201102) Stock Area: Georges Bank
Age Reader*: NS vs. BH Date Completed: Summer 2011
Number Tested: 186    
CV: 2.42% Agreement: 91.4%
Bowker's test: Not applicable
  *The U.S. age reader is listed first; this is not meant to imply that either reader's ages are expected to be more reliable.


A. Agreement Plot

Cod Agreement Plot

B. Age-Frequency Table

Age Age (BH)
(NS) 0 1 2 3 4 5 6 7 8 9 Total
Total 1 70 66 9 14 4 21 1 186
0
1
2 1 63 3 67
3 7 63 2 72
4 7 7
5 11 11
6 4 4
7 2 21 23
8 1 1
9 1 1


C. Results Summary

Age (BH) N N Agreed Percent Agreed Average Age (NS)
1 1 0 0 % 2.00
2 70 63 90 % 2.10
3 66 63 95 % 2.95
4 9 7 78 % 3.78
5 14 11 79 % 5.50
6 4 4 100 % 6.00
7 21 21 100 % 7.00
8
9 1 1 100 % 9.00


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