Constant over interval The values are quantities that can be interpreted as constant for all time, or over the time interval to a subsequent measurement of the same variable at the same site. 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.