I don't have the 2/08 issue right here, but in the Letters column, someone (JA?) commented that perhaps blind tests don't have "sufficient resolving power" to pick up differences that ears can hear. The easiest way to increase the statistical power of a blind test is to increase the number of blind raters. Given reasonable listening conditions (e.g., familiar source material, components other than what's being tested that are familiar to the raters, sufficient listening time), the more listeners you have, the more chance that a difference noticed by the raters is not the result of chance. Basic statistics...
I don't have the 2/08 issue right here, but in the Letters column, someone (JA?) commented that perhaps blind tests don't have "sufficient resolving power" to pick up differences that ears can hear. The easiest way to increase the statistical power of a blind test is to increase the number of blind raters. Given reasonable listening conditions (e.g., familiar source material, components other than what's being tested that are familiar to the raters, sufficient listening time), the more listeners you have, the more chance that a difference noticed by the raters is not the result of chance. Basic statistics...