confounding variables

基本解释

This is a problem in nearly every study, and even in studies controlling for known confounding variables, residual confounding remains a concern.
这几乎每个研究都存在的问题，甚至在控制已知混杂因素的研究中，其他的混杂因素依然受到人们的关注。
The study sounds simple, but the design of the experiments was actually somewhat complex, because the researchers had to overcome a number of confounding variables.
这个实验听起来很简单，但是实验的设计确实有一定程度的复杂性，因为研究人员不得不克服一些混淆变量。
They also knew that, by working with surveys from three countries, and with such a wide range of ages, they would diversify the data and iron out confounding variables.
他们也明白研究三个国家的调查结果，而且是这么广的年龄跨度，他们能使数据多样化且消除混杂变量。

Dr Wilson and Dr Storm restricted their study to white, Protestant teenagers, in order to eliminate confounding variables.
ECONOMIST: Human evolution
This was despite nearly identical power outputs in all four tests and efforts to control for possible confounding variables, such as the time of day.
ECONOMIST: Exercise and company
By a useful (though hardly unexpected) coincidence, all the businessmen were male and all were white, so there were no confounding variables of race or sex.
ECONOMIST: Physiognomy and success: Face value