Encoding refers to the content or form in which information is stored in memory; forgetting is loss of the stored information with the passage of time or with exposure to interfering materials; and retrieval refers to accessing information from memory. Any observation of memory reflects all three components, but measurements of recognition time, reflecting memory search, emphasize retrieval. Recognition time is the time required to respond whether a visually presented test item was part of a previously studied list. For an example of a recognition test following a short-term memory list, see Figure 1. Recognition time and accuracy for individual items in both short-term and long-term memory are consistent with retrieval mechanisms involving parallel, or direct access, operations rather than unguided search through many memories. Some aspects of the increase in recognition time with the length of small short-term memory lists suggest a serial, or sequential, search...