ALK tolerance mismatch between OM and EM can cause a large bias in SSB
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- Dominant language
- R
- Stars
- 21
- Forks
- 14
- PR merge metrics
- No merged PRs in 30d
Description
Thanks to the sardine team for pointing this out! In the OM, the ALK tolerance setting is reset to 0, as Rick Methot has recommended turning off tail compression in an OM. However, nothing is done for EM's, so in a sardine model with ALK tolerance of 0.001 in the EM, there was a large bias in SSB between OM and EM (and the EM had estimation issues). Setting the ALK tolerance to 0 as well for the EM seems to solve the issue.
A potential solution would be to reset ALK tolerance to 0 in EMs as well or at least warning users to consider doing this.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
The issue names no files or tests; start by locating where ALK tolerance is configured for operating models (OMs) and estimation models (EMs). Compare how the two paths handle the setting, then verify that the chosen fix prevents SSB bias and EM estimation issues for the sardine case.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- r
- Domain
- data
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100