OPERATOR VARIANCE IN THE DETERMINATION OF THE PLASTIC LIMIT,
Abstract
An experiment designed to investigate operator variance in determining the plastic limit of cohesive soils, independent of sample preparation and hydration time, is reported. A standard sample of Grundite and pure silt was prepared, the sample was hydrated for 3 weeks, 5 random samples were taken, and 5 replicates performed on each sample. Analysis of variance showed that the sample was homogeneous at the 0.05 level of significance. Random samples were distributed to 5 zones (groups) of operators, each with different backgrounds and engineering interests. Two operators from each group performed 5 replicates. The analysis-of-variance model used in the analysis was mixed, and the upper level fixed and the 2 lower levels random. The estimated within and between operator variances were 0.45 and 4.18, respectively. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1963
- Accession Number
- AD0433188
Entities
People
- G. E. Ballard
- Wilford Frank Weeks
Organizations
- Cold Regions Research and Engineering Laboratory