
Accession Number : ADA135408
Title : Development of Statistical Techniques to Better Utilize Data Characterized by Being Below Instrument Detection Thresholds and by Small Sample Size.
Descriptive Note : Final rept. 1 Jul 8231 Aug 83,
Corporate Author : VERSAR INC SPRINGFIELD VA
Personal Author(s) : Gleit,A S
PDF Url : ADA135408
Report Date : 24 Oct 1983
Pagination or Media Count : 76
Abstract : Estimation of parametric families for small data sets where a significant portion of the data lay below fixed instrument detection thresholds was investigated. Thus the number of data points was random (an example of Type I censoring). Both analytic and simulation procedures were utilized. In particular, maximum likelihood techniques, order statistic techniques, truncation techniques, fillin with constants, and fillin with expected values of the missing points were investigated. For exponential data, truncation seemed most appropriate while for normal and lognormal data, fillin with expected values (modified to correct for conditioning on the number of data points) was best. The criteria for selection was the total square error. (Author)
Descriptors : *Statistical processes, *Data management, Experimental data, Statistical data, Air Force research, Data bases, Maximum likelihood estimation, Estimates, Order statistics, Threshold effects, Truncation
Subject Categories : Statistics and Probability
Distribution Statement : APPROVED FOR PUBLIC RELEASE