Estimation of Treatment Difference Following a Sequential Clinical Trial Author(s): Eva Skovlund and Lars Walloe Reviewed work(s): Source: Journal of the American Statistical Association, Vol. 84, No. 407 (Sep., 1989), pp. 823- 828 Published by: American Statistical Association Stable URL: http://www.jstor.org/stable/2289673 . Accessed: 17/08/2012 04:18 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp . JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. . American Statistical Association is collaborating with JSTOR to digitize, preserve and extend access to Journal of the American Statistical Association. http://www.jstor.org