 Partial report paradigm

A partial report paradigm asks an observer to report a selected subset of presented material. It can estimate available information while reducing the burden of reporting everything. A selection cue before presentation and a cue after presentation test different possibilities: the former can guide initial attention, whereas the latter selects from information that remains available after the display.

George Sperling used brief visual arrays and post-exposure instructions to separate available visual information from whole-report limits. Tone cues could specify a row or reporting order after the symbols disappeared.^[ref]

In an invented three-row display with four symbols per row, suppose the cued row is selected uniformly and an observer correctly reports an average of three symbols from it. Under equal-sampling and accessibility assumptions, the inferred available count across the display is $3\times 3=9$ of the twelve symbols. This is a sampling argument, not an observation of nine simultaneous verbal responses, and the numbers are not Sperling's measured data.

Delaying the selection cue probes changes in availability over time. A declining partial-report advantage can indicate loss of accessible information, but selection, retrieval and output demands must also be considered. The partial report paradigm therefore links perception and sensory memory to experimentally specified responses without equating every report failure with a failure to see.