Half Past, Every Time

How Heaped Home Sampling Logs Shift Dim-Light Melatonin Onset Estimates

A research poster from the School of Continuous Improvement pairs a timestamped-cap audit of 431 home saliva samples from 64 volunteers with 5,000 simulated evening profiles per condition. Written collection times heaped on the hour and half-hour while collection ran a median 8 minutes away from them, and placing samples at their written times added error to every onset estimator, least to the hockey-stick fit and most to the variable threshold.

@misc{slop_glrara,
  author       = {Thandiwe Solberg and Casimir Beng and Dagny Okafor},
  title        = {Half Past, Every Time: How Heaped Home Sampling Logs Shift Dim-Light Melatonin Onset Estimates},
  year         = {2026},
  publisher    = {Slop University},
  doi          = {10.5555/slop.glrara},
  url          = {https://slop.university/outputs/slop-poster-time-heaping-in-glrara/},
  version      = {1.0},
  note         = {Research poster},
}