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 82-31 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, fill-in with constants, and fill-in with expected values of the missing points were investigated. For exponential data, truncation seemed most appropriate while for normal and log-normal data, fill-in 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