Is it permissible for women to be seated at the back of a lecture hall without a barrier separating them from men, knowing that they will not be able to see the events if there is a barrier, or should they be placed in a separate room to watch the events via television broadcast?

If the seminar is religiously permissible or culturally beneficial, and the women therein are observing a complete, শরعي hijab, and there is no intermingling or other religious transgressions—meaning the men are seated in the front rows and the women behind them at an appropriate distance—then there is no harm in that, even if there is no barrier between the men and women. Sheikh Ibn Baz mentioned that women praying behind men in the mosque without a barrier was present during the time of the Prophet, peace be upon him. His saying, "The best of men's rows is the first and the worst is the last, and the best of women's rows is the last and the worst is the first," indicates that the matter is broad in this regard. If a wall, curtain, or screen is provided for the women for their comfort, there is no objection to that either, and there should be no over-strictness in this matter.