In this thesis, I examine Americans' preferences for and performance with three different types of visuals in instructions: cartoon-like images, photographs, and line drawings. Using an electronic survey and usability tests, I conclude that though Americans of most ages generally dislike cartoon-like images and tend to prefer photographs and line drawings, performance for two specific age groups exhibiting dislike (those under 24 years of age and over 50) demonstrates increased success using cartoon-like images. This finding suggests that technical communicators need to conduct usability tests for multiple age groups. In addition, I explain that more research on methodology is necessary.