Statistical Models for the Analysis of Ageing Error
We present statistical models for estimating the true age distribution of a population, based on multiple readings from individual fish. There are two steps to this process. The first involves estimating a classification matrix that defines the probability of assigning an age a to a fish when its tr...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Canadian Science Publishing
1992
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Online Access: | http://dx.doi.org/10.1139/f92-200 http://www.nrcresearchpress.com/doi/pdf/10.1139/f92-200 |
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crcansciencepubl:10.1139/f92-200 2024-06-23T07:57:11+00:00 Statistical Models for the Analysis of Ageing Error Richards, Laura J. Schnute, Jon T. Kronlund, A. R. Beamish, Richard J. 1992 http://dx.doi.org/10.1139/f92-200 http://www.nrcresearchpress.com/doi/pdf/10.1139/f92-200 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 49, issue 9, page 1801-1815 ISSN 0706-652X 1205-7533 journal-article 1992 crcansciencepubl https://doi.org/10.1139/f92-200 2024-06-06T04:11:18Z We present statistical models for estimating the true age distribution of a population, based on multiple readings from individual fish. There are two steps to this process. The first involves estimating a classification matrix that defines the probability of assigning an age a to a fish when its true age is b. Since true age is unknown, we require an assumption related to ageing error bias; we assume that the true age is the most probable value for the observed age. True age proportions, or alternatively, true ages of fish in the sample are then estimated in the second step. Our methods allow us either to conduct both steps simultaneously or to estimate true age proportions from a previously estimated classification matrix. We illustrate our methods with data on walleye pollock (Theragra chalcogramma). We recommend that multiple independent readings be obtained for a subset of structures in future ageing studies and that ageing error be considered in subsequent analyses. Sample sizes must be increased with increasing ageing error to achieve a specified precision in estimates of true age proportions. Article in Journal/Newspaper Theragra chalcogramma Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences 49 9 1801 1815 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
We present statistical models for estimating the true age distribution of a population, based on multiple readings from individual fish. There are two steps to this process. The first involves estimating a classification matrix that defines the probability of assigning an age a to a fish when its true age is b. Since true age is unknown, we require an assumption related to ageing error bias; we assume that the true age is the most probable value for the observed age. True age proportions, or alternatively, true ages of fish in the sample are then estimated in the second step. Our methods allow us either to conduct both steps simultaneously or to estimate true age proportions from a previously estimated classification matrix. We illustrate our methods with data on walleye pollock (Theragra chalcogramma). We recommend that multiple independent readings be obtained for a subset of structures in future ageing studies and that ageing error be considered in subsequent analyses. Sample sizes must be increased with increasing ageing error to achieve a specified precision in estimates of true age proportions. |
format |
Article in Journal/Newspaper |
author |
Richards, Laura J. Schnute, Jon T. Kronlund, A. R. Beamish, Richard J. |
spellingShingle |
Richards, Laura J. Schnute, Jon T. Kronlund, A. R. Beamish, Richard J. Statistical Models for the Analysis of Ageing Error |
author_facet |
Richards, Laura J. Schnute, Jon T. Kronlund, A. R. Beamish, Richard J. |
author_sort |
Richards, Laura J. |
title |
Statistical Models for the Analysis of Ageing Error |
title_short |
Statistical Models for the Analysis of Ageing Error |
title_full |
Statistical Models for the Analysis of Ageing Error |
title_fullStr |
Statistical Models for the Analysis of Ageing Error |
title_full_unstemmed |
Statistical Models for the Analysis of Ageing Error |
title_sort |
statistical models for the analysis of ageing error |
publisher |
Canadian Science Publishing |
publishDate |
1992 |
url |
http://dx.doi.org/10.1139/f92-200 http://www.nrcresearchpress.com/doi/pdf/10.1139/f92-200 |
genre |
Theragra chalcogramma |
genre_facet |
Theragra chalcogramma |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 49, issue 9, page 1801-1815 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f92-200 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
49 |
container_issue |
9 |
container_start_page |
1801 |
op_container_end_page |
1815 |
_version_ |
1802650695021625344 |