External facing websites (ie available to those outside of the university population) should probably have a common look and feel. Large corporations use that common look and feel to protect (and project) their image, I would assume that a University would want to do the same thing.

We did some research on this topic a while back, analyzing the websites of universities in the field of design and hci. From the interviews of students and pupils interested in studying as well as companies interested in collaborations, we can say that more structure would be good. What may be interesting for you is the fact, that a lot of the big university sites already have a common information architecture by helping people to navigate the website by supporting special navigation routes for students, people interested in studying, as well as other target audiences like press or alumni. Just to give an example look at www.tu-berlin.de

there must be some kind of standard which basically taking in considerations three points , accessible , user friendly , and EDI

I agree with point of Sebestian Meier.. Well-planned and comon Information architecture will keep users away from any sort of confusion. In addition, Juneidi also raised good points. Informaton architecture is like human health..You feel it when you fall sick. Therefore, universities should define some sort of standard which include at least Information Architecture, Rules for Web site design as well as accessibility, usability and Human computer interaction