Transfer and retention of implicit and explicit learning.

Two parallel tasks involving rule learning were used to assess implicit and explicit learning. The complex task (occurring in the complex rule-line condition) involves predominantly implicit learning, and the simple task (occurring in the simple rule-number condition) requires primarily explicit learning. Implicit learning clearly showed negative transfer from previous implicit learning experience, whereas explicit learning showed strong positive transfer. Subjects' explicit knowledge declined and implicit knowledge remained at the same level when retested one week later. The results are discussed in terms of principles guiding the learning and transfer of explicit and implicit knowledge. This is consistent with the assertion that implicit and explicit learning involve two functionally different learning systems.