The visual design and layout of websites and online data collection tools influences how people perceive, navigate and understand the information presented, as well as how they interact with the instrument. Visual design principles can be used to help the user recognize the most important information on the page and guide how they interact with specific features. For this study we use visual design principles to inform the design of a website that is intended to provide and collect information from research participants in a longitudinal panel and then evaluate the design of the website. The measures we use to evaluate the design include both passive measures, such as eye-tracking and performance data, and active measures, such as user think-aloud comments and answers to standardized questions in order to understand how people perceive the information on the site and navigate certain features. We will focus these findings on the evaluation of specific components on the site, including the organization of information, navigation tabs, use of images, card displays and edit buttons. Since this website will ultimately be used by a diverse population, the influence of respondent characteristics (e.g., age, race, computer literacy), and how to account for these characteristics through visual design, will also be discussed. We will present quantitative and qualitative findings related to each of these components and discuss how the information is used to improve the visual design of this website, as well as other websites with similar goals. In addition, the findings from the study will be used to provide best practices or guidelines for presenting particular types of information on websites and online data collection instruments.