1. A system comprising: at least one hardware device processor; and at least one machine readable storage device storing instructions that, when executed, cause one or more of the at least one hardware device processor to: iteratively obtain a plurality of incremental query results and a plurality of confidence interval values associated with respective ones of the incremental query results, each respective one of the incremental query results generated as a respective, temporally progressively generated part of an answer to an initial query, the respective incremental query results representing respective incremental results of a plurality of incremental queries operating on temporally progressively larger samples from a database; iteratively determine a plurality of visualization shape objects indicating uncertainty values, based on mapping values of respective ones of the incremental query results and confidence interval values to points in the associated ones of the visualization shape objects, the uncertainty values visualized based on proportional shapes of the visualization shape objects; determine at least one visualization comparison object representing a comparison of a plurality of distributions associated with the obtained incremental query results and confidence interval values; and iteratively display the plurality of visualization shape objects and the at least one visualization comparison object.