Clinical trials take a long time because they're rigorously controlled, with close attention paid to samplingbias and methodology.
临床试验需要花费很长时间,因为它们处于严格控制之下,必须密切留意取样偏差与方法。
2
In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of survey data.
除了采样误差,在调查中提问的措辞和一些实际困难也会导致在采集数据中产生误差或偏差。
3
But critics have a point that genetic police work, like the sampling of arrestees, is fraught with bias.