Closing the Knowledge-Practice Gap

In 1954, Dr. Jonas Salk organized a large, double-blind, randomized, placebo-controlled experiment to determine whether his vaccine was effective. Some children were given the vaccine (and only the vaccine); others were given an identical looking placebo (a salt solution). The choice about who would (and who would not) receive the vaccine was done randomly; no human could influence (even unconsciously or indirectly) the choice. Moreover, neither the children, their parents, those who administered the vaccine, nor the doctors who examined the children knew whether the child received the vaccine or the placebo. Unfortunately, public executives rarely have the opportunity to conduct such an experiment. Still, they need to look for the best available evidence and put it into practice.