Like a steady drip from a leaky faucet, the experimental studies being released this school year by the federal Institute of Education Sciences are mostly producing the same results: "No effects," "No effects," "No effects." The disappointing yield is prompting researchers, product developers, and other experts to question the design of the studies, whether the methodology they use is suited to the messy real world of education, and whether the projects are worth the cost, which has run as high as $14.4 million in the case of one such study. But proponents of the methodology say those critics ought to pay more attention to the message than to the messenger.