When I was GATE vice-chairman for three years during 2004-2007, there were lot of discussions to make it online. Though I was technically savvy among the members, I was the person who strongly protested against this. The reason was three fold: (a) the number of students taking GATE is much higher than exams like GRE (For GATE 2010, the numbers have crossed 4 lakhs) (b) creation of question banks with several questions in each subject area (c) the unwillingness to outsource it to a separate agency.
Unlike GRE/CAT etc, GATE has multiple papers and, therefore, large question banks have to be developed for each subject. Further, levels of each question should be established because if different students take the exam on different days, the level of the exam should be similar. Setting up these questions takes time and willingness of several faculty involved.
Many people in the committee felt that the exam should not be outsourced but be conducted locally and that IISc/IIT should conduct the exam for around 2 lakh students over 10 days (like CAT) but not outsource it. This would mean creation of huge infrastructure, security features etc. done by people whose expertise is not in this area. Now, because of the debacle of CAT online exam, we know that outsourcing it to a good company also does not work all the time.
Of course, the long term solution is to have an online exam. This year, GATE will conduct online exam for two small papers (textile and mining). These papers have very small number of students taking the exam and can be conducted in only the IITs/IISc (eight centers). I do not envisage any problems with this. But as numbers increase and it becomes impossible to conduct the exam on a single day, the issue of question banks and thousands of computers come in. Maybe the next step for IIT/IISc is to conduct JMET (single question paper, lesser students) online, learn from this and then try to conduct any other major exam like GATE/JEE online. I repeat what I said in 2005, "Hasten slowly."