4. A computer-readable storage device whose contents, if executed by a computing system, cause the computing system to explore information relating to a population by: displaying a graphical report reflecting information relating to the entire population; in conjunction with the graphical report, displaying a control enabling a user to select a named segment of the population among a plurality of named segments of the population; receiving input indicating that the user has operated the displayed control to select a named segment of the population; in response to receiving the input, displaying in place of the graphical report reflecting information relating to the entire population a graphical report reflecting information relating to only the selected named segment of the population; displaying a control enabling a user to select one of a plurality of report types; and receiving input indicating that the user has operated the displayed control to select a report type, and wherein the displayed graphical report reflecting information relating to the entire population is of the selected report type.
4. A computer-readable storage device whose contents, if executed by a computing system, cause the computing system to explore information relating to a population by: displaying a graphical report reflecting information relating to the entire population; in conjunction with the graphical report, displaying a control enabling a user to select a named segment of the population among a plurality of named segments of the population; receiving input indicating that the user has operated the displayed control to select a named segment of the population; in response to receiving the input, displaying in place of the graphical report reflecting information relating to the entire population a graphical report reflecting information relating to only the selected named segment of the population; displaying a control enabling a user to select one of a plurality of report types; and receiving input indicating that the user has operated the displayed control to select a report type, and wherein the displayed graphical report reflecting information relating to the entire population is of the selected report type. 5. The computer-readable storage device of claim 4 wherein the displayed control enables a user to select a named subset of the population among a plurality of named subsets of the population organized into a hierarchy of population subsets.