[quoting Oliver, 21 Oct 96] Here's a scenario which may help. I run Steven's experiment with a group of known poor readers. Just to be thorough, I run a second trial with a group of visually impaired subjects. To be even more thorough, I get hold of a group of newly arrived immigrants from Slovenia who have only been learning English for two weeks and, through a translator, get them to agree to take part.
What's the point here? Obviously blind people will not learn as well from books as from radio. When Clark said media don't influence learning, he was talking about the "normal" case of students drawn from the normal population. Surely Clark was not saying that media make no difference to people who have some handicap which prevents them from using a certain medium. That violates common sense.
If you think there was something abnormal about my students let's hear it. I can't imagine what it could be.
The groups are presented with a pencil and paper post-test and can't read well enough to answer the questions. I scrub that test and repeat it using audio questions and write down the verbal answers from the students. Apart from the new immigrants who seemed to perform poorly all round, the groups perform better when learning from audio input. I proudly conclude that "media matter." Steven, what's wrong with my conclusion? Wouldn't you agree that the skewed abilities of the sample groups are more significant than the media?
Your conclusion is too broad. You can only conclude (trivially) that media matter for the kinds of special populations your sample was drawn from. You don't need an experiment to find that out.
My sample was drawn from typical university students, therefore my conclusions apply to that population. Can you point to any special disability in my students that would cause a random group of them to learn better from reading than another random group that listened to the exact same text?
And please don't say "Clark was no better." Your experiments must stand in their own right to be worthy of serious consideration.
I never said that. Clark performed no experiments so I couldn't have said it.
I suggest that controlling extraneous variables is at the heart of any worthwhile research and I don't think you did that. Will you not concede that your experiment was flawed and that your conclusion is unlikely to have any validity?
What extraneous variables were not controlled? I will concede nothing.