We created a series of videos for an online introductory astronomy course at the Pennsylvania State University in part to address the lack of personal presence in online courses. Based on surveys administered to the students during the semester, we found that these videos were effective in creating an instructor presence within the online course. We also found that students who perceived a strong instructor presence had a more positive attitude toward the course. Additionally, there is a correlation between the students' perceptions of how helpful a video is with how enjoyable they rated it, but no correlation between the perceived helpfulness of a video and student performance on video-specific questions, suggesting that students are not good at assessing video helpfulness. (Contains 1 table and 3 figures.)