Precision Templates for Ageing

February 26, 2020

These templates were designed to automate the calculation of measures of ageing precision (including percent agreement, coefficient of variance, and symmetry tests) and plot results for paired age data.

A series of templates were designed to automate the calculation of measures of ageing precision, including percent agreement and the total coefficient of variance (CV, Chang 1982), plus generating both an agreement plot and an age matrix table. Most of these measures were recommended by Campana et al. (1995). In the precision templates, symmetry is also tested with a Bowker's test (Hoenig et al. 1995) if the percent agreement drops below 90 percent. The templates run in Excel* (Microsoft Office).

Available Templates

These templates are designed to compare paired ages from one age reader, but can easily be relabeled for comparisons of two different readers or structures. Click on each title to download the corresponding template. (All files are less than 100 kb.) If clicking on the link doesn't work, try "Save Link as..."

  • Standard Precision Template:
    Compares paired ages for samples with ages from 0 to 16.
  • Expanded Precision Template (25 year max):
    Compares paired ages for samples with ages 0 to 25.
  • Expanded Precision Template (30 year max):
    Compares paired ages for samples with ages from 1 to 30.
  • Expanded Precision Template (50 year max):
    Compares paired ages for samples with ages from 1 to 50. Also calculates percent agreement with a ±1 'forgiveness factor'.
  • Accuracy Template:
    Compares test ages against known ages, for samples with ages from 0 to 16. Does not calculate a test of symmetry.
  • Symmetry Template (16 year max):
    Calculates two symmetry statistics, Bowker's (unpooled) and Evans-Hoenig (diagonally-pooled). Accepts ages up to 16 years and age differences up to 10 years.
  • Symmetry Template (50 year max):
    Calculates the Bowker's test of symmetry for samples with ages up to 50 years and age differences of up to 10 years.

Basic instructions can be found within each template. This PDF contains detailed directions for using the templates. You may also download the entire set of templates (ZIP folder). All templates were created by Sandy Sutherland at NOAA Fisheries.

*Use of trade or brand names in any NEFSC publication or report does not imply endorsement.

Last updated by Northeast Fisheries Science Center on 06/15/2020

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