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That's actually how statistics works. You don't need 100,000+ people to make a readily generalizable conclusion. If the differences are significant, they'll ap

That's actually how statistics works. You don't need 100,000+ people to make a readily generalizable conclusion. If the differences are significant, they'll appear with as few as 35 people, carefully selected, and give you a confidence level of X that it applies to a population size of Y. Whilst I don't know the details of this particular study, I do recall doing homework problems about correlation confidence. In layman's terms, maybe this example will help: Imagine a study where they found that 100% of people who were "sitting" had bent knees. Essentially no one could bring their hips and ankles closer together without bending their knees. With such a significant correlation, you could generalize from a population of 10 to one of trillions so long as the ten was randomly chosen, and there were no other correlative factors.

pbhjpbhj 9y ago
Aside from things like false legs and injury bringing your hips and ankles together like that is a physical impossibility; that doesn't provide a good analogue. People sit with straight legs too, but if you test by asking people to sit on a chair it will show everyone sits with bent knees, where in fact lots of people sit on the floor, beach, or bed (say) with straight legs. FWIW I sit on a chair with straight legs, on top of my computer tower. If you take a sample of 35 people in China you can with a reasonable confidence level say all people are Chinese, or perhaps a very small proportion aren't, depends how lucky you get. It's wrong of course, despite Chinese being the majority (17% according to Wikipedia). It's fine as a preliminary, but it doesn't show anything useful yet other than the need to perform further study IMO. A report on this should say something like "viability study suggests sitting and brain changes are related but doesn't provide enough confidence as yet". Which it sorta does, from this section on: >"This study does not prove that too much sitting causes thinner brain structures, but instead that more hours spent sitting are associated with thinner regions, researchers said." But either ScienceDaily or UCLA have not lead with that information, matching the current style.

pbhjpbhj 9y ago

Aside from things like false legs and injury bringing your hips and ankles together like that is a physical impossibility; that doesn't provide a good analogue. People sit with straight legs too, but if you test by asking people to sit on a chair it will show everyone sits with bent knees, where in fact lots of people sit on the floor, beach, or bed (say) with straight legs. FWIW I sit on a chair with straight legs, on top of my computer tower. If you take a sample of 35 people in China you can with a reasonable confidence level say all people are Chinese, or perhaps a very small proportion aren't, depends how lucky you get. It's wrong of course, despite Chinese being the majority (17% according to Wikipedia). It's fine as a preliminary, but it doesn't show anything useful yet other than the need to perform further study IMO. A report on this should say something like "viability study suggests sitting and brain changes are related but doesn't provide enough confidence as yet". Which it sorta does, from this section on: >"This study does not prove that too much sitting causes thinner brain structures, but instead that more hours spent sitting are associated with thinner regions, researchers said." But either ScienceDaily or UCLA have not lead with that information, matching the current style.