This Perspective article expands on a working memory-dependent dual-process model, originally proposed by Zheng et al., to elucidate individual differences in the testing effect. This model posits that the testing effect comprises two processes: retrieval-attempt and post-retrieval re-encoding. We substantiate this model with empirical evidence and propose future research. This model invites further studies on the trade-off between testing benefits and WM demands, facilitating the development of personalized educational practices.