> Is there any question here that this has happened?
Yes. The notion that our capacity for "concentration and contemplation" has been diminished is a testable claim, of which I have seen no evidence, and I would approach any attempt to quantify that with an enormous amount of skepticism. (It's a hard thing to quantify in a meaningful way, and easy to do poorly.) Further showing that any such diminished capacity is caused by how we consume information online is even more difficult, and as far as I know, not done.
Information access is so cheap today that the framework for how I learn now is very different than how it was when I was growing up 25 years ago.
Most knowledge is bundled up into bite-sized chunks and indexed by Google. In 1991, you'd be consulting a reference manual or some other physical medium to get the information to answer a question. Today, that answer is pre-interpreted and available on Stack Exchange via Google.
That said to master your craft, whatever it is, still requires that attention to detail and complemative approach.
I think by the fact that you are already looking for ways to disapprove the research (Which you say doesn't exist yet) your point gets lost.
And given I'd say most people on HN take it as fact the the internet has caused concentration and contemplation issues you need evidence of the opposite.
With everyone believing something on anecdotal evidence it becomes up to the opposing view.
I disagree (obviously). It means that I have strong priors, in the Bayseian sense, because I have heard of poorly done studies that try to answer similar questions. I am also aware of what I consider to be a significant issue with replication in psychological studies (something which has been on HN frequently).
Yes. The notion that our capacity for "concentration and contemplation" has been diminished is a testable claim, of which I have seen no evidence, and I would approach any attempt to quantify that with an enormous amount of skepticism. (It's a hard thing to quantify in a meaningful way, and easy to do poorly.) Further showing that any such diminished capacity is caused by how we consume information online is even more difficult, and as far as I know, not done.