At Science, Marc Kirschner notes
Scientists often face vexing professional decisions: whom to hire, what to fund, what to publish, and whom to promote. Because science is about the unknown and its greatest discoveries are often the least expected, scientists often have little to go by except intuition and experience. For this reason, a seductively simple template has recently been introduced: assessment based on “impact and significance.” Thus, the U.S. National Institutes of Health has elevated “significance” to an explicit criterion in funding decisions. It requires that grant reviewers write a paragraph on “impact,” which it defines as the likelihood that the proposed work will have a “sustained and powerful influence.”* Especially in fundamental research, which historically underlies the greatest innovation, the people doing the work often cannot themselves anticipate the ways in which it may bring human benefit. Thus, under the guise of an objective assessment of impact, such requirements invite exaggerated claims of the importance of the predictable outcomes-which are unlikely to be the most important ones. This is both misleading and dangerous.