On time differences in searching for letters in words and nonwords: do they emerge during the initial encoding or the subsequent scan?

Krueger (1970a, 1970b, 1982) has demonstrated that subjects can search for target letters within words faster than they can complete an equivalent search through nonwords, and he further demonstrated that the effect did not arise during the comparison stage. The present study involved three experiments in which the usual word advantage disappeared either when subjects knew where within a display the target item would appear (i.e., it was always the first letter), or when all the component letters were encoded into memory before the task began (i.e., a memory-search task). These data, in conjunction with Krueger's, where interpreted as localizing at least one (and possibly the only) source of the word-nonword difference in this task to the events that occur during the item-to-item transitions subjects make when scanning the letter arrays. That is, these transitions are faster for words than nonwords, and it was suggested that the time difference may emerge because although all the letters from within a word appear to be available in memory before the scan begins, this seems not to be true for consonant arrays. Given that this is the case, part of the word-nonword difference may be attributable to subsequent encoding events that would be needed for the consonant arrays as the scan moves from letter to letter.