Visualizations are an integral part of education, and the features of visualizations have been associated with differences in learning and generalization. I propose that students use the features of visualizations, such as their perceptual richness, as cues to infer the generality of the information presented in lessons. I test this proposal in 10 studies that examine the impact of perceptual richness on biology learning. Chapter 1 provides a comprehensive review of the literature on multi-media learning and how people learn with visualizations and articulates how people might use richness as a cue for generalization. Chapter 2 presents two experiments that examine how perceptual richness influences how adults learn and generalize the concept of metamorphosis, how these effects might change over time, and how they depend on the similarity of the test items to the exemplar in the lesson. Chapter 3 presents one content analysis and six experiments examining how children and adults integrate textual characteristics and the richness of visualizations when learning and generalizing animal facts. Chapter 4 presents an experiment that examines how parents and children learn and generalize the concept of evolution when they learn from a book with rich or bland images. Chapter 5 presents an integrated discussion of all of these studies that highlights how people use richness as a cue to infer the generality of lessons, and also highlights how this depends on characteristics of the lesson, learner, task and context. I also propose that a socio-cultural perspective might be a useful framework to understand how people learn and generalize from multi-media lessons, and I discuss the implications for cognitive and developmental psychology and biology education. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]