Sounds like they’re running the experiment. The first scenario you described is a good illustration of the kind of effort it would take to ensure no effect. The

Sounds like they’re running the experiment. The first scenario you described is a good illustration of the kind of effort it would take to ensure no effect. The second? I’d be interested in knowing how they find families and decide what books to include. I’d expect (and I admit I hope) it will have a measurable efect. I’ll search for it but please post a link if you have one.