AP Psychology Practice Test

Relearning measures the reduction in time or effort required to learn previously learned material again. This concept is crucial in understanding memory retention and retrieval. When an individual revisits information or skills that they have previously learned, the process often takes less time than it did during the initial learning phase, indicating that some memory of the material was retained.

This phenomenon highlights the efficiency of memory; even if the information isn't readily recalled, it can be acquired more quickly upon subsequent attempts. This method of measurement is important in various educational and therapeutic contexts, as it reflects the strength and durability of prior learning experiences.

The other options revolve around different aspects of memory, such as recognition or mood-dependent memory, which do not specifically encapsulate the idea of relearning as a measure of efficiency in acquiring previously encountered material.