李攀 发表于 2014-7-13 07:54 
问题很大的,厦大这样的学校,更不要说一般的学校
We may consider the possibility by sampling.
In other words, the population is very large, making a census or a complete enumeration of all the values in the population impractical or impossible.
The sample represents a subset of manageable size. Samples are collected and statistics are calculated from the samples so that one can make inferences or extrapolations from the sample to the population.
This process of collecting information from a sample is referred to as sampling. The data sample may be drawn from a population without replacement, in which case it is a subset of a population; or with replacement, in which case it is a multisubset.
With sufficient evidence, we can provide the assurance service to our client universities.