Sorry, AuntyM, I'm still scratching my head because I still think you're preaching to the choir....UNLESS:

you're saying that you think that, in the hands of an inexperienced angler, the fish lost/landed ratio is exactly the same (or the difference is statistically insignificant) between those hooked on barbed or barbless hooks.

It seems to me that logic would dictate that if the line goes slack, as is common in the hands of an inexperienced angler, a hook with a barb that's penetrated the tissue of a fish's mouth is much more likely to stay put. If there's data to the contrary (controlled testing and all that) I'm all for examining it.