What "spacing" actually asks of a repetition
Spacing means spreading repetitions of the same material across time rather than cramming them together. The interesting question for paraphrasing is whether a second exposure that says the same thing in different words counts as a genuine repetition, or whether it is different enough that the learner treats it as new material.
The 1987 study by Glover and Corkill is the closest direct test: students read verbatim repetitions of paragraphs, some massed and some spaced across time, and other students read paraphrased versions [1]. That design puts paraphrasing and spacing in the same experiment, which is exactly the comparison the question asks about. But the available abstract does not state which condition produced better retention, so it supports the framing of the question more than a specific verdict.
Why changing the words might change what gets stored
A paraphrase keeps the meaning but swaps the surface wording. If memory stores the gist, a paraphrased repeat could reinforce the same underlying idea; if memory leans on exact wording, a paraphrase may feel like a different item and do less to strengthen the original trace.
The 2024 study on false claims speaks to this distinction. When a claim was repeated word-for-word or only in gist, both produced high and roughly equal levels of belief while the claim was not disconfirmed [3]. That suggests gist repetition is powerful enough to match verbatim repetition for at least one outcome, belief. The same study found that a later correction lowered belief more effectively after verbatim repetition than after gist repetition [3], so the two formats are not equivalent in every respect.
Questions about wording are not the same as questions about timing
It is easy to blur two different manipulations: changing the wording of a repetition and changing the gap between repetitions. The 1978 study on adjunct questions compared verbatim and paraphrased questions inserted into prose, and it did not examine spacing at all [2]. Its relevance to the spacing question is therefore indirect: it concerns how wording of a repetition affects learning from text, not how timing does.
That gap matters for interpreting the answer. The 2024 belief study also does not test spacing; it compares verbatim and gist repetition without varying the interval between them [3]. So the strongest evidence here establishes that verbatim and paraphrased (gist) repetitions can behave differently, not that they produce comparable spacing effects.
What a learner or teacher should do with this
If the goal is durable memory, the safest reading is to keep spaced repetition in the schedule and treat paraphrasing as a supplement rather than a substitute. Paraphrased repeats appear able to reinforce an idea, since gist repetition matched verbatim repetition in producing belief [3], but the evidence does not show that a paraphrase spaced across time works as well as an exact repeat spaced across time.
For material where exact wording matters, such as definitions or corrections of false claims, verbatim repetition has an edge: corrections were more effective after word-for-word repetition than after gist repetition [3]. For material where the idea matters more than the phrasing, a paraphrase may still be worth including, but the spacing comparison itself remains unresolved in the available evidence [1].
Sources used in this answer
Influence of paraphrased repetitions on the spacing effect.
The study compares massed and spaced verbatim repetitions of paragraphs with paraphrased versions, directly examining how paraphrasing relates to the spacing effect.
Verbatim and paraphrased adjunct questions and learning from prose.
The study compares verbatim and paraphrased adjunct questions for learning from prose but does not address spacing effects.
False information is harder to debunk after gist repetitions than verbatim repetitions
Gist and verbatim repetitions produced similarly high belief in undisconfirmed false claims, but a later correction was more effective after verbatim than after gist repetition.