An outlier problem in the determination of ore grade

Brenton Clarke and Toby Lewis

Journal of Applied Statistics, 1998, vol. 25, issue 6, 751-762

Abstract: Data from recordings of ore assays from the Western Australian goldfields provide motivation to devise new tests for outliers when observations are distributed with the same mean but diff ering variances. In the case of equal variances, tests for a single outlier reduce to well-known tests of discordancy. A block discordancy test for k outliers is also described. The question of whether or not one should omit any observation(s) in the calculation of the mean recoverable gold content is addressed in the context of whether or not the data contain outliers, as judged by a normal model for the 'logged' ore assay values. The given data suggest that models with 'logged' values that follow long-tailed approximately normal distributions may be appropriate.

Date: 1998
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
http://www.tandfonline.com/doi/abs/10.1080/02664769822747 (text/html)
Access to full text is restricted to subscribers.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:taf:japsta:v:25:y:1998:i:6:p:751-762

Ordering information: This journal article can be ordered from
http://www.tandfonline.com/pricing/journal/CJAS20

DOI: 10.1080/02664769822747

Access Statistics for this article

Journal of Applied Statistics is currently edited by Robert Aykroyd

More articles in Journal of Applied Statistics from Taylor & Francis Journals
Bibliographic data for series maintained by Chris Longhurst ().