About half of American households own stocks. Something close to the same percentage thinks the stock market is more volatile than it should be.

I recently met up with longtime New York Stock Exchange floor trader Doreen Mogavero. She talked about what we've learned from wild market volatility like the 2010 flash crash, and what we can do to help prevent future meltdowns. Have a look (transcript follows):

Doreen Mogavero: Well I think we are learning as we go. We are fixing the system, but I think a computer is a machine, right? Machines break, and that in good part is why you always need people to somewhat back them up. I couldn't say it would never happen again; we would hope that it would not happen again, but I think the likelihood that machines will break again, probably pretty good. So I think you really need people here to make sure that when they do break, we continue to trade.

A good part of what I think the New York Stock Exchange floor provides for the investors is confidence. I tell all my clients, a machine can break. That's a problem. But you would have to kill me; you would actually have to kill me to have me stop trading here, so I think the investors should take some comfort in the fact that their money will always be accessible, as long as there are people here to trade it.

Fool contributor Morgan Housel has no position in any stocks mentioned. The Motley Fool recommends NYSE Euronext. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.