Editing Iconic memory (section)

== Sperling's partial report procedure ==
In 1960, [[George Sperling]] became the first to use a partial report paradigm to investigate the bipartite model of VSTM.<ref name = "Sperling"/>  In Sperling's initial experiments in 1960, observers were presented with a [[Tachistoscope|tachistoscopic]] visual stimulus for a brief  period of time (50 ms) consisting of either a 3x3 or 3x4 array of alphanumeric characters such as: 
:<kbd>P Y F G</kbd>
:<kbd>V J S A</kbd>
:<kbd>D H B U</kbd>

Recall was based on a cue which followed the offset of the stimulus and directed the subject to recall a specific line of letters from the initial display. Memory performance was compared under two conditions: whole report and partial report.

=== Whole report ===
[[File:Sperling's Partial Report Paradigm.jpg|thumb|Sperling's original partial report paradigm.]]
The '''whole report''' condition required participants to recall as many elements from the original display in their proper spatial locations as possible. Participants were typically able to recall three to five characters from the twelve character display (~35%).<ref name = "Sperling"/> This suggests that whole report is limited by a memory system with a capacity of four-to-five items.

=== Partial report ===
The '''partial report''' condition required participants to identify a subset of the characters from the visual display using [[Recall (memory)#Cued recall|cued recall]]. The cue was a tone which sounded at various time intervals (~50 ms) following the offset of the stimulus. The frequency of the tone (high, medium, or low) indicated which set of characters within the display were to be reported. Due to the fact that participants did not know which row would be cued for recall, performance in the partial report condition can be regarded as a random sample of an observer's memory for the entire display. This type of sampling revealed that immediately after stimulus offset, participants could recall a given row (from a 3x3 grid of 9 letters) on 75% of trials, suggesting that 75% of the entire visual display (75% of 9-letters) was accessible to memory.<ref name = "Sperling"/>  This is a dramatic increase in the hypothesized capacity of iconic memory derived from full-report trials.