Hypothesized that the repetition of alphabetical coding cues between lists would increase retroactive inhibition (RI) in free-recall learning (FRL). The amount of alphabetical coding was varied by instructions to some Ss to use alphabetical cues in learning and instructions to others for free recall; overlap in cues was manipulated by the assignment of some Ss to learn materials with the same 12 1st letters in the 2 lists (2 words/cue), and some to learn lists with 12 different 1st letters. List 1 was learned to a criterion of 16/24 correct responses and List 2 was presented for 6 trials. Control Ss learned a single list and worked on arithmetic problems for the duration of List 2 learning. Following the interpolated activity, Ss recalled, in any order, the words of the list(s) they had learned. Results support the hypothesis, with a large increase in RI for Ss who were required to use the same alphabetical cues in both lists. (15 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)