Best easy systematic estimator Best Easy Systematic Estimator BES = (Q1 +2Q2 +Q3)/4. Q1, Q2, and Q3 are first, second, and third quartiles. See Woodcock, F. and Engel, C., 2005: Operational Consensus Forecasts.Weather and Forecasting, 20, 101-111. (http://www.bom.gov.au/nmoc/bulletins/60/article_by_Woodcock_in_Weather_and_Forecasting.pdf) and Wonnacott, T. H., and R. J. Wonnacott, 1972: Introductory Statistics. Wiley, 510 pp. Adapted from CUAHSI HIS DataTypeCV. See http://his.cuahsi.org/mastercvreg/edit_cv11.aspx?tbl=DataTy ODM2 Aggregation Statistic Controlled Vocabulary ODM2 Working Group A vocabulary for describing the calculated statistic associated with recorded observations. The aggregation statistic is calculated over the time aggregation interval associated with the recorded observation.