The word-length effect and disyllabic words

Three experiments compared immediate serial recall of disyllabic words that differed on spoken duration. Two sets of long- and short-duration words we re selected, in each case maximizing duration differences bur matching for frequency; familiarity phonological similarity and number of phonemes, and controlling for semantic associations. Serial recall measures were obtained using auditory and visual presentation and spoken and picture-pointing rec all. In Experiments la and Ib, using the first set of items, long words wer e better recalled than short words. In Experiments 2a and 2b, using the sec ond set of items, no difference was found between long and short disyllabic words. Experiment 3 confirmed the large advantage for short-duration words in the word set originally selected by Baddeley, Thomson, and Buchanan (19 75). These findings suggest that there is no reliable advantage for short-d uration disyllables in span tasks, and that previous accounts of a word-len gth effect in disyllables are based on accidental differences between list items. The failure to find an effect of word duration casts doubt on theori es that propose that the capacity of memory span is determined by the durat ion of list items or the decay rate of phonological information in short-te rm memory.