As in Experiment 1, we computed d′ scores to compare older and younger adults’ recognition memory performance in the Forced Choice and Yes/No Tests at each block length (Macmillan & Creelman, 1991). Before exploring the effects of interference on performance, we first assessed performance when our two groups faced an equivalent amount of interference, namely for the reference block containing 180 stimuli, which is depicted in Figure 3 (left; raw scores in Table 3). To this end, we conducted a 2 × 2 mixed ANOVA with Test Format (FC, YN) as a within-subject factor and Age (young, old) as a between-subjects factor. The results replicated those observed in Experiment 1, with (a) both older and younger adults performing significantly better in the Forced Choice test relative to the Yes/No test, F(1, 77) = 15.15, p < .001, ηp2 = 0.164, (b) older adults performing significantly worse than younger adults across both test formats, F(1, 77) = 10.13, p < .005, ηp2 = 0.116, and (c) the size of this age effect being equivalent across test formats (F < 1).