Studying on borrowed time: How does testing impair new learning?

Area of Science:

• Cognitive Psychology
• Educational Psychology
• Learning Sciences

Background:

• Retrieval practice is known to enhance subsequent learning of new material.
• However, retrieval has also been observed to impair new learning, creating a paradox in the literature.

Purpose of the Study:

• To investigate the conditions under which retrieval practice enhances versus impairs new learning.
• To test the 'borrowed time hypothesis' which posits that impaired learning occurs when testing is intermixed with new learning.

Main Methods:

• Participants' learning was assessed under conditions where retrieval (testing) and new learning were either intermixed or presented in separate blocks.
• Interventions were employed to discourage 'time borrowing'—relearning tested material at the expense of new material.

Main Results:

• Intermixing retrieval and new learning trials led to impaired new learning, supporting the borrowed time hypothesis.
• Separating retrieval and new learning into distinct blocks eliminated this impairment and often enhanced new learning.
• Discouraging time borrowing also reduced or eliminated the impairment in new learning.

Conclusions:

• Test-impaired new learning and test-enhanced new learning are distinct phenomena, not simply opposite outcomes of the same process.
• The arrangement of retrieval and new learning (intermixed vs. blocked) critically determines whether retrieval practice aids or hinders subsequent learning.