WHY IS THE ALPHABETICALLY MIDDLE LETTER IN A MULTILETTER ARRAY SO HARD TO DETERMINE - MEMORY PROCESSES IN LINEAR-ORDER INFORMATION-PROCESSING

In 3 experiments, participants identified target letters in multilette r strings of different interletter steps. Results show that the alphab etically extreme targets in the arrays (A or C in BCA) were consistent ly identified faster than were the interior letters, with the alphabet ically middle target (B in BCA) identified most slowly. Distance effec ts were not consistent across different targets. The findings are not consistent with the ends-inward serial search, comparison, and serial search plus comparison models. The data suggest that an interior targe t was identified by first identifying the terminal letter and then men tally constructing the linear order inward by probabilistically using either a comparison or an interitem serial search process to achieve m aximal efficacy. This suggestion is consistent with the ends-inward co nstruction theory of linear-order learning.