Spaced Study vs. Cramming: What Actually Improves Retention
Spaced study, distributing review sessions over time with growing intervals between them, produces meaningfully stronger long-term retention than cramming the same total study time into one intensive session shortly before an exam — cramming can still be a reasonable, if imperfect, strategy specifically for very short-term recall needs, but it's a poor strategy for material that needs to be retained well beyond the exam itself.
This comparison isn't simply about which strategy is generally "better" — it's about matching the strategy to what actually needs to happen with the material afterward.
When spaced study is clearly the better choice
For material that builds toward future coursework, a cumulative final exam, or genuine long-term understanding of a subject, spaced study's stronger retention advantage makes it the clearly better strategy — the whole point of learning that material is undermined if it's forgotten shortly after the immediate exam.
When cramming is a more defensible, if imperfect, choice
For material needed only for a single, isolated short-term assessment with no further relevance afterward, cramming's weaker long-term retention matters less, since long-term retention isn't actually the goal in that specific narrow case — though even here, cramming carries real risk, since exam performance itself depends on more reliable recall than cramming reliably produces.
A realistic middle ground
For most real academic situations, some combination — spaced study for the bulk of preparation, with a final, focused review session close to the exam — captures spaced study's retention benefit while still including a concentrated final review that reinforces confidence and catches any weak spots close to the actual exam date.