Web-based surveys have become increasingly popular with researchers. Unfortunately, they are subject to the same response rate issues that plague traditional surveys. This entry briefly reviews some of the theories about why individuals elect or decline to participate in surveys. It then discusses methods that might be considered when a researcher is thinking about how to improve survey responses. The methods are divided into two categories: the first category includes methods adapted from traditional mail surveys such as using incentives, pre-notifications, survey invitations, and reminders. The second category includes methods specific to Web-based surveys, including Web-based survey design and confidentiality issues.