Do delayed judgements of learning reduce metamemory illusions? A meta-analysis

Past research has shown that the perceptual characteristics of studied items (e.g., font size) lead to a metamemory illusion, and that delayed judgements of learning (JOLs) are better predictors of memory performance than immediate JOLs. Here, we tested whether delayed JOLs could reduce or eliminate the effect of perceptual characteristics on JOLs and restudy decisions. We adopted a meta-analytic approach and analysed the results of 28 experiments in which participants' studied items were presented in either large or small font. JOLs and, sometimes, restudy decisions were collected either immediately or after a delay. Finally, participants completed a memory test. The results of the meta-analyses confirmed the effect of the font size on JOLs and restudy decisions. The delayed procedures reliably reduced the effect of perceptual characteristics on JOLs, but the effect was still significant after a delay. For restudy decisions, delayed procedures only reduced numerically the effect. Surprisingly, the meta-analysis also showed a very subtle memory advantage for items presented in large font over small font, although no individual study showed a significant difference and the overall effect size was small. One plausible explanation is that after a delay, information about font size is not available for some items, causing a reduction in the effect. Moreover, our results suggest that the dissociation between memory and metamemory reported previously may not be dissociation at all, but a mistmatched effect of font size on memory and metamemory.