I would never make it as a teacher: my lesson plan for such a field trip would include telling the students to choose a painting and look at it for five minutes in complete silence. I've been told that five minutes is a long time for school children, but when I tried it, I found the picture to be so much more interesting that I think the students should have that opportunity. In groups, they’re not encouraged to spend any significant amount of time actually looking at anything.
This is why one of the only school field trips I’ve really thought worthwhile was the elementary school “gifted class” trip to the Living Seas at EPCOT, where the kids were free to choose what they wanted to do, and my group spent 15 minutes of their precious time at one window of the aquarium, just watching—and commenting on—the fish. If children are going to be rushed from one activity to another, with no time to observe, to absorb, and to consider, then let's not waste time and money misleading them. It's nothing short of fraud, under such circumstances, to let them, their parents, and taxpayers believe they've experienced anything important of what a museum has to offer.