根据以下材料，回答26-30题<br /> A poll of Nature's readers suggests that feelings about metrics are mixed.Many researchers say that, in principle, they welcome the use of quantitative performance metrics because of the potential for clarity and objectivity.Yet they also worry that the hiring, promotion and tenure committees that control their fate will ignore crucial but hard-to-quantify aspects of scientific performance such as mentor ship and collaboration building,and instead focus exclusively on a handful of easy-to-measure numbers related mostly to their publication and citation rates.<br /> Academic administrators contacted by Nature suggest that this fear may be exaggerated.Most institutions seem to take a gratifyingly nuanced approach to hiring and tenure decisions, relying less on numbers and more on wide-ranging,qualitative assessments of a candidate's performance made by experts in the relevant field.<br /> Yet such enlightenednuancing cannot be taken for granted.Numbers can be surprisingly seductive, and evaluation committees need to guard against letting a superficial precision undermine their time-consuming assessment of a scientist's full body of work.This is particularly true in countries such as Britain, where metrics-heavy national assessments of universities can trickle down, so that individuals feel more rewarded for quantity than for quality--and change theirbehavior to match.<br /> New measures of scientific impact are being developed all the time, in part driven by government agencies looking to quantify the results they are getting for their investment.Such innovation is to be encouraged.But researchers must be mindful of how and why the metrics they are making are being used.There needs to be much discussion between specialists such as social scientists, economists and scientometricians to ensure that metrics development goes hand-in-hand with a discussion of what the metrics are for, and how they are affecting people.Only then can good suggestions be made about how to improve the system.<br /> Academic administrators, conversely, need to understand what the various metrics can and cannot tell them.Many measures—including the classic"impact factor" that attempts to describe a journal's influence—were not designed to assess individual scientists.Yet people still sometimes try to apply them in that way.Given that scientometricians continue to devise metrics of ever-increasing sophistication, universities and scientific societies need to help decision-makers keep abreast.Setting a good example is the European Summer School for Scientometrics, a program that is being inaugurated in Berlin.It promises a science-based approach to tutoring on the merits and pitfalls of various metrics.<br /> Institutions must also ensure that they give their researchers a clear and complete picture of how assessments are made.This can be awkward—but transparency is essential：no matter how earnestly evaluation committees say that they are assessing the full body of a scientist's work, not being open about the criteria breeds the impression that a fixed number of publications is a strict requirement, that teaching is undervalued and that service to the community is worthless.Such impressions do more than breed discontent--they alter the way that scientists behave.To promote good science, those doors must be opened wide.<br /> What can we infer from the last paragraph?