Addictive Behaviors published a study conducted by researchers at the University of Michigan Substance Abuse Center which concluded that web-based surveys are as effective in gathering some kinds of data about substance abuse as mail-based surveys.1 The authors issued a survey on the "secondary consequences" of substance use to 7,000 undergraduate students, who were randomly assigned to equal-sized groups (n = 3500). Each group was asked to respond either by mail or by a web-based survey. Statistical analysis of the results revealed "minimal differences between Web and mail survey modes in the reporting of secondary consequences associated with substance use."

In a previous study carried out by several of the same authors, the researchers found that a web-based survey can be an effective tool in gathering data "in an economically and racially diverse urban sample of secondary students".2 This study found statistically-similar response patterns for over 1,500 secondary school students in responding to substance abuse surveys.

These findings support our belief at Erowid that meaningful data on psychoactive substance use may be gathered through web-based surveys, such as the series of eight LSD surveys Erowid conducted between October 2005 and January 2006. While some self-selection bias is inevitable in any survey, data collected through web-based surveys appears to be as valid as that from traditional paper-based surveys.