Is there a temporal basis of the word length effect? A response to Service (1998)

Service (1998) carried out a study of the word length effect with Finnish pseudowords in which short and long pseudowords were identical except for the inclusion of certain phonemes differing only in pronunciation length, a manipulation that is impossible in English. She obtained an effect of phonemic complexity but little or no word duration effect per se--a discrepancy from the expectations generated by the well-known working memory model of Baddeley (1986). In the present study using English words, we controlled for phonemic complexity differences by using the same words for the short- and long-word sets, but with instructions inducing shorter or longer pronunciation of the words. We obtained substantial word duration effects. Concerns raised by Service are addressed, and we conclude that both duration and complexity are likely to contribute to the word length effect in serial recall.