The answer to the question depends on the purpose of the evaluation. If the purpose of the evaluation is to inform, rather than to judge, then anybody is qualified to express an opinion which can be considered with respect to the organization's aims. On the other hand, if students' evaluations become a means for judging the quality of the teaching then there could be a number of potential misconceptions and misunderstandings:

　　"差学生"蓄意给老师打低分，好学生参与度不高。

　　One of my observations regarding the evaluation by students is, that more often the disappointed and underperforming students express their dissatisfaction most intensively, while good and content students prefer to be quiet, or they are just like that, and often are reluctant even in participating in such surveys which distorts the real situation in a class and draws a rather bad picture.

　　数据有问题；领导没有安全感所以给老师打分；老师为了得到高分

　　不负责的先给学生高分。

　　My personal experience reveals that (1) instruments used in teacher's evaluation by students are poorly developed and the data gathered from the survey have not been properly analyzed; (2) not every student is truthful in the evaluations; (3) insecure leaders of the school use the evaluation as a means to show that they are doing something to improve the learning environments and learning. However, the fact is they are not only insecure but also incompetent; (4) teachers who want to get high evaluations tend to lower their teaching or assessment standards so that students can get higher grades and therefore give more positive evaluations. In short, if the instruments are the traditional ones that we commonly encounter, then I advice against the practice.

　　In a university where the students are from diverse backgrounds, student evaluations will be less consistent, depending on each student's perceptions of the reasons for being there and expectations of the teaching process based on their previous experiences. Therefore, in addition to looking at the average ratings (which is the most commonly used index), evaluators will need to be trained to look at other characteristics of the data, such as the nature of the distribution, its skewness and its variance.

　　重点搭配和句子摘抄：

　　a means for xxx ：一个xxx的方法

　　potential misconceptions and misunderstandings: 潜在的错觉和误解

　　express an opinion ：表达一个观点

　　the purpose of the evaluation ：评估的目的

　　disappointed and underperforming students ：失望且表现差的学生

　　good and content students ：满意的好学生

　　distorts the real situation ：歪曲真实的情况

　　have not been properly analyzed：被分析的很糟糕

　　are not only insecure but also incompetent：不仅没有安全感而且很无能

　　lower their teaching or assessment standards ：降低讲课和评估的标准

　　are from diverse backgrounds：来自不同的背景

　　the nature of the distribution, its skewness and its variance：分布、偏度和方差（统计学中专业的词汇）

　　适用题目：

　　Teachers' performance should be evaluated by students rather than by other teachers.