Background: How to improve learning with online multimedia lessons has attracted widespread concern. Prior studies have attempted to help students learn by breaking a video lesson into several segments. However, there has been a debate about whether learners can use pause time effectively and whether prompting them to engage in different types of generative learning activities during pauses can better facilitate learning. Objectives: This study aimed to explore how to maximize learning by asking students to engage in generative processing activities during pauses in segmented narrated video lessons. Methods: Three experiments explored the effectiveness of segmenting, and whether adding summaries between segments can improve learning performance. In Experiment 1, participants were asked to view a segmented video or a continuous video. In Experiment 2, we examined whether adding summarizing activities during pauses can improve the effects of segmenting. In Experiment 3, we further investigated the effects of adding different types of summarizing activities during pauses. Results and Conclusions: In Experiment 1, segmenting improved performance on retention tests, but not on transfer tests. In Experiment 2, the effects of segmenting on the retention and transfer tests were enhanced when learners were asked to produce written summaries during the pauses. In Experiment 3, asking participants to imagine or write summaries during the pauses in segmented lessons improved retention and transfer test performance, but providing a summary only helped on retention. Takeaways: Adding generative learning activities (i.e., summarizing) during pauses prompted learners to learn the material more deeply. Results are consistent with the ICAP framework and the cognitive theory of multimedia learning.