One of the basic results about free recall is the serial-position curve which is a function giving probability of recall as a function of position of the item in the input sequence. Murdock (1962) gathered some data looking at recall of lists that varied in length from 10 to 40 words, presented at 1 or 2 seconds for each word. These results show the classic recency effect, which is the high level of recall at the end of the list, and the primacy effect, which is the somewhat higher level of recall at the beginning of the list. The performance level is somewhat flat in intermediate positions with levels higher for shorter lists or for lists with more study time.