The use of web-based surveys to gather information from teachers has become increasingly common primarily based on the premise that they can reduce costs. Yet, relatively, little is known about the quality or cost effectiveness of web-based versus mail surveys for teachers. To study the efficacy of web-based teacher surveys, the author randomly assigned a nationally representative sample of 877 elementary school teachers to a paper or web survey mode. The cost savings from the web administration were not enough to offset the loss of sample due to missing/inaccurate email addresses and the lower response rates that resulted from the web survey. (Contains 10 tables and 1 figure.)