Which statement about evidence and long-term retention is true?

• A. Regularly testing yourself does not improve long-term retention.
• B. Re-reading notes is more effective than retrieval practice for long-term retention.
• C. Spacing out study sessions over time and retrieval practice together is not more effective than cramming.
• D. Spacing out study sessions over time and retrieval practice together improves long-term retention more than cramming.

Answer: (D)

Spacing study sessions over time and using retrieval practice together yields stronger long-term retention than cramming. The reason is twofold: spacing helps memory by reducing forgetting and promoting durable consolidation, while retrieval practice actively strengthens memory traces each time you recall information. When you combine both, you get repeated, effortful recall spread across time, which reinforces learning more deeply and makes it easier to retrieve later. Cramming, by contrast, relies on quick learning in a single session and often leads to rapid forgetting, especially after a delay. So the evidence supports that distributing study and testing yourself over time produces the best long-term retention. The other statements contradict these findings: testing does improve long-term retention, re-reading is typically less effective than retrieval practice, and spacing plus retrieval practice outperforms cramming.