Soybean yield modeling using bootstrap methods for small samples
Soybean yield modeling using bootstrap methods for small samples
Gustavo H. Dalposso, Miguel A. Uribe-Opazo and Jerry A. Johann
http://dx.doi.org/10.5424/sjar/2016143-8635
Abstract: One of the problems that occur when working with regression models is regarding the sample size; once the statistical methodsused in inferential analyzes are asymptotic if the sample is small the analysis may be compromised because the estimates will bebiased. An alternative is to use the bootstrap methodology, which in its non-parametric version does not need to guess or know theprobability distribution that generated the original sample. In this work we used a set of soybean yield data and physical andchemical soil properties formed with fewer samples to determine a multiple linear regression model. Bootstrap methods were usedfor variable selection, identification of influential points and for determination of confidence intervals of the model parameters. Theresults showed that the bootstrap methods enabled us to select the physical and chemical soil properties, which were significant inthe construction of the soybean yield regression model, construct the confidence intervals of the parameters and identify the pointsthat had great influence on the estimated parameters.Additional
key words: multiple linear regression; model selection; bootstrap global influence diagnosis; bootstrap confidence intervals.