2004/03/05 by R. J. Barlow, Roger Barlow, Barlow, Roger
Decision Sciences · Physics and Astronomy · #Advanced Statistical Process Monitoring #Data Analysis #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Probabilistic and Robust Engineering Design #Scientific Measurement and Uncertainty Evaluation #Statistics and Probability (physics.data-an) #hep-ex #physics.data-an
paper · pdf · doi:10.48550/arxiv.physics/0403046
7 pages. 2 figures
arxiv created 2004/03/05 · openalex publication_date 2004/03/05 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
The points at which the log likelihood falls by 1/2 from its maximum value are often used to give the `errors' on a result, i.e. the 68% central confidence interval. The validity of this is examined for two simple cases: a lifetime measurement and a Poisson measurement. Results are compared with the exact Neyman construction and with the simple Bartlett approximation. It is shown that the accuracy of the log likelihood method is poor, and the Bartlett construction explains why it is flawed.