Conducted 5 probe experiments to investigate the extraction of information from briefly presented arrays of letters. Ss were a total of 88 undergraduates. The 1st 2 experiments used a spatial single-item bar marker procedure. Results show a W-shape function of accuracy with stimulus position. The last 3 experiments investigated the use of a single item probe in which Ss examined each item in the array to indicate the presence or absence of a critical target; reaction time was the dependent measure. Results show that search through brief arrays of letters proceeded item by item and from left to right, as evidenced by an increase in reaction time from left to right and an increase in reaction time for the negative responses. A small order of approximation effect was exhibited in all experiments; this effect was attributed to guessing and was a precategorical analysis of the visual information. (17 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved)