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Complex survey samples are constructed with selection schemes that affect the usual random assumptions, so SAS/STAT ® software provides specialized procedures to analyze them: SURVEYMEANS, SURVEYFREQ, SUR-VEYREG, and SURVEYLOGISTIC for means, frequencies, regression, and logistic analysis, respectively. These procedures all use the Taylor series expansion(More)
The Cox proportional hazards model is widely used in practice to estimate the effects of covariates on survival function. The SAS/STAT ® PHREG procedure is a long-standing workhorse for performing regression analysis for event-time data based on the proportional hazards model. However, special techniques are required when the subjects are selected through(More)
Small area estimators commonly borrow strength from other related areas. These indirect estimators use models (explicit or implicit) that relate the small areas through supplementary data. Various unit-level and area-level small area models are proposed in the literature, but all these models assume the small area mean is linearly related with supplementary(More)
In the past, designing probability samples for biological field studies has been limited by the difficulty of locating random points in the field. The ability to receive precise GPS signals in many field settings has largely removed this constraint. We have been investigating statistical and computer-based technologies that enable field data collectors to(More)
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