The effects of irrelevant relations on the processing of sequential patterns.

Letter series completion problems varying along location of irrelevant relations (beginning, end, none) were presented to 24 Ss. A repeated-measures analysis of solution times and errors revealed that irrelevant relations at the beginning of series produced the longest latencies and the most errors. Using a pattern induction/sequence production model of serial processing, an error analysis showed production error rate remained constant across treatments, while pattern induction errors varied with confusion location. The results indicate that the difficulty of sequential processing varies with irrelevant relations only during the pattern induction phase. The findings also support a left-right generate-and-test model of pattern induction for the task.