 Abstract: Participants were provided an alphabetical list of the United States presidents and were given two tasks with the list. They ordered the presidents according to terms in office in the semantic task and a pseudorandom sequence shown previously in the episodic task . Both tasks yielded bow-shaped serial position functions, but the recency effect (for the last three positions) was much larger and the penultimate effect (for the nine preceding positions) was evident only in the semantic task , which was also affected by participant age. Recency effects were similar in episodic lists of presidents and actors. Familiarity ratings yielded serial position functions like those in the semantic task . These findings suggest that serial position effects in semantic and episodic memory tasks are not caused by the same underlying mechanism and that prior frequency of exposure to order information is responsible for these effects in the semantic task . 
