Plants, Pathogens, and People is a Web site promoting agricultural awareness via multimedia lectures about plant diseases and online lab activities in which students investigate phenomena. The use of the site in large-enrollment classes for 6-plus years affords a well-documented case of Web-enhanced instruction. Qualitative and quantitative data on student perceptions of the site, their learning, and the relation of the Web site to the course as a whole provide insights into both the benefits and the challenges of Web-based teaching and learning. Students rate the site as an enhancement to their learning, but there are differential responses to various components of the site, which provide a fuller picture of how students see Web-based learning relating to their overall educational experience.