While it may be true that this new procedure may have a direct implication on student's grades, we don't have enough evidence to support the assumptions that are beyond this argument. It's not hard to imagine a teacher be encouraged to inflate his student's grades just to have a better evaluation from his students, however, without reliable data supporting this statement, Omega University should not terminate this procedure without first further analyze the issue.
Citing a rise of 30% in grades, the author explains that the new method of evaluting teachers is the main responsible for it. However, this statement alone it's not clear and valid. More evidence is required, like for example, evidence that allows us to compare the level of cognitive capacity of students enrolled in Omega University today and 15 years ago. Evidence about the overall level of difficulty of the programme and the criteria of evaluation should also be compared. If by any chance, the students are more capable, or the different courses offered by this university have the same difficulty, the original argument to terminate the procedure becomes weaker, because we found that this rise in grades is not mainly provoked by the new method of evaluation of teachers.
Additionally, the author of the argument explains that potencial employers believe that grades in Omega University are inflated, making them undervalue the students. Again, the author gives a big step by justifying the underperforming of the students with the rise in grades. In order for this statement to hold, we would have to compare how recent undergraduate students would perform in the market 15 years ago with today. We should then find evidence about a decrease in real salaries and employment rate ,for students with similar grades, in these last 15 years. We should also find data about the university rankings, because this drop may be related with a decrease in the quality of the university, and not just because student's grades have risen. If we find that the university quality became constant through these last 15 years, but students are underperforming, then we have evidence that strengthens the argument. If not, the original author's position will be weakened.
Building upon this last implication that the students are underperforming in the market place due to the inflation of grades, the author also suggests that the Omega graduates are less sucessfull Alpha graduates due to this phenomenon. Another time, to prove this statement, we have to find evidence. For it, we should compare the two universities. Maybe Alpha graduates perform better because their university offers a better programme, so it has a better talent pool. Alpha University may also have better partnerships than Omega, so, when their sudents graduate, they have immediatelly better offers. We should also find data that compares this differences now and 15 years ago. Maybe Omega graduates are not underperforming as much today as they were 15 years ago, even if they are still less sucessfull. So, if we have data that shows that are real differences between the two universities, and these changes are reflected on how their graduates are valued, the author's arguments is weakened.
A teacher's evaluation method based on student's opinions oftens leads to a more soft method of evaluation by the teachers, which can lead to a increase in grades. For this reason the university may have a reason to terminate this new procedure. However, this argument should have solid evidence behind, otherwise the university's admnstration is unlikely to be persuaded by it.