> There could be an over-represented subgroup of the general population who are more susceptible to the cell phone radiation, but selecting from that group would not necessarily obscure the relationship between the amount of cell phone use and any resulting biological impact.
That's not what he said. If you read the abstract, it says that the candidates were chosen using "questionnaires accessing demographic data and characteristics of cell phone usage were completed by 106 men referred for semen analysis." The fact that they were referred for semen analysis (read: they were having trouble reproducing) indicates there'd be a selection bias in their study. And without a control group, it's all hand-waving anyway.
> They don't go very far out on the limb, they say that it probably justifies a bigger study, which is pretty mild.
In order to do it properly, they'd need a much bigger study and a much better sample.
My point was that the selection bias proposed will not necessarily obscure a biological effect (or at least, correlation).
Setting aside the legitimacy of pursuing this research, looking for effects using statistical analyses of medical records is an interesting way to direct at least a small amount of research, saying that such questions can only be asked when there is solid control of every factor is probably not a win.
> My point was that the selection bias proposed will not necessarily obscure a biological effect (or at least, correlation).
I'd argue that the sample was not representative of the general population, so "it will not necessarily obscure" isn't relevant IMO because the results aren't even remotely close to being applicable to any other group of men.
> looking for effects using statistical analyses of medical records is an interesting way to direct at least a small amount of research
I agree that it's interesting. And since I can't read the paper at the moment (I'll download a copy through my university when I get a chance) I can't really comment on the statistical methods they used (I'm not even sure what they asked on the questionnaire). Statistical analysis is only useful if you take into account all of the parameter space (or at least all of the significant parameter space) otherwise you'll get a biased result.
Even then, correlation does not imply causation, so a statistical analysis would only be useful as a survey of "what could be investigated to do actual science on". People put far too much faith into statistics, and it
> saying that such questions can only be asked when there is solid control of every factor is probably not a win
Anyone can ask a question. I'm saying that the paper published should've actually been an email (or maybe just an article) sent around a faculty so they could do real research on the topic. "Asking a question" and "publishing a paper on a topic" are very different classes of activities.
That's not what he said. If you read the abstract, it says that the candidates were chosen using "questionnaires accessing demographic data and characteristics of cell phone usage were completed by 106 men referred for semen analysis." The fact that they were referred for semen analysis (read: they were having trouble reproducing) indicates there'd be a selection bias in their study. And without a control group, it's all hand-waving anyway.
> They don't go very far out on the limb, they say that it probably justifies a bigger study, which is pretty mild.
In order to do it properly, they'd need a much bigger study and a much better sample.