Abstract: A wealth of researches has indicated that retrieval practice can be used as an effective means to improve memory. Recently the effects of retrieval practice have captured the attention of contemporary researchers who are interested in educational applications of retrieval practice. Some researchers have examined the effectiveness of retrieval practice relative to elaborative studying with concept mapping, and found that practicing retrieval produces greater gains in meaningful learning than elaborative studying with concept mapping which has received comment and query by researchers advocating constructivism who thought, compared with practice retrieval, concept mapping is too complex to master. In view of these criticism, the current research examined the effectiveness of retrieval practice and concept mapping from the perspective of cognitive load, it is hypothesized that the intrinsic load of study task which depends on learners’ prior knowledge level has different influence on retrieval practice and concept mapping, and the concept mapping strategy is more complex than retrieval practice, so it could produce more extraneous load on learner and influence the effectiveness. Two experiments were conducted to test the hypotheses. In experiment 1, 120 college students were engaged in a 2 (prior knowledge level: high vs. low) × 3 (study strategy type: retrieval practice vs. concept mapping and repeated study) between-subjects design of experiment, which was aimed to study the different influence of prior knowledge level on the effectiveness of three types of strategies. In experiment 2, 43 college students participated in a within-subjects design of experiment, each student completed a partial concept mapping of one science text and practiced retrieval of a second text which was designed to study the influence of strategy’s complexity on strategy’s effectiveness. The results indicated that on correct rate of memory retention and transfer, the main effect of prior knowledge level wasn't significant, but there was an interaction between learning strategies and prior knowledge level: under the condition of retrieval practice strategy, there is no significant difference on the correct rate of retention and transfer between participates with high prior knowledge and participates with low prior knowledge; as the concept mapping strategy concerned, the participates with high prior knowledge were significantly higher than participates with low prior knowledge on the correct rate of retention and transfer. In addition, the complexity of the strategy would increase learners' extraneous load, but it didn't have decisive influence on the effectiveness of the strategy. In terms of result, it was concluded that the reason why retrieval practice could produce more memory retention and transfer than concept mapping is not because of that its strategy is easier to be master, it is that the concept mapping strategy was very dependent on learner's prior knowledge level. Relatively, retrieval practice is not dependent on learner's prior knowledge level. The results have some important implications. Firstly, retrieval practice is an effective tool to promote retention and transfer, it indeed can enhance subsequent recall more than concept mapping. Thus, educators should pay more attention to the effectiveness of retrieval practice rather than view it as an assessment device to measure what a student knows. Secondly, the findings support the theory that retrieval practice enhances learning by retrieval-specific mechanisms rather than by elaborative study processes.

Key words: retrieval practice, concept mapping, cognitive load, prior knowledge level, elaborative study processes