Serial position, output order, and list length effects for words presented on smartphones over very long intervals

- Novel smartphone presentation of experimentally-controlled word lists.
- Strong temporal contiguity effects in free recall at rates of 1 word per hour.
- Shallow serial position effects in free recall at rates of 1 word per hour.
- Shallow primacy effects in serial recall at rates of 1 word per hour.
- Recency in recognition of experimental words presented over 50 days.

Three experiments examined whether or not benchmark findings observed in the immediate retrieval from episodic memory are similarly observed over much greater time-scales. Participants were presented with experimentally-controlled lists of words at the very slow rate of one word every hour using an iPhone recall application, RECAPP, which was also used to recall the words in either any order (free recall: Experiments 1 to 3) or the same order as presented (serial recall: Experiment 3). We found strong temporal contiguity effects, weak serial position effects with very limited recency, and clear list length effects in free recall; clear primacy effects and classic error gradients in serial recall; and recency effects in a final two-alternative forced choice recognition task (Experiments 2 and 3). Our findings extend the timescales over which temporal contiguity effects have been observed, but failed to find consistent evidence for strong long-term recency effects with experimenter-controlled stimuli.