Scientific evidence (was British Homeopathy Backlash)
Posted: Wed Oct 10, 2007 6:36 pm
Both my husband and I were trained as scientists, so I have a bias towards "real" science, instead of junk science. When I say "scientific evidence," I mean evidence that supports an assumption of causation (X causes Y).
"Scientific evidence" means experimental evidence. You take two or more groups of homogenous mice, randomly assign them to the experimental and control groups, and measure how they react to one specific variable X. If X leads to Y in one group, but not in the control group, then one can tentatively assume that it is possible X causes Y.
Or you can experiment with people, but that is hard to come by because of ethical constraints. That is why most of what we know about human health is correlational and anecdotal.
Correlational evidence is when you study the population at large and notice that correlations between X and Y. This type of evidence does not support any conclusion of causation, because it is possible that a third variable, Z, actually causes both X and Y.
Anecdotal evidence is when you hear about X causing Y in one person, or 200 persons, or 5000 persons. It is not scientific because there was no randomization and no control comparisons. We don't know if X "caused" Y in these people because of some common factor Z that they all share, and that it is really Z causing both X and Y.
Most of the evidence supporting homeopathy would be considered anecdotal by the scientific community. However, just because something is anecdotal doesn't mean it isn't true. It just means, without experimental data, that there isn't yet any scientific proof that it is true.
I hope that clarifies what I mean when I use these terms.
Best,
Helen
"Scientific evidence" means experimental evidence. You take two or more groups of homogenous mice, randomly assign them to the experimental and control groups, and measure how they react to one specific variable X. If X leads to Y in one group, but not in the control group, then one can tentatively assume that it is possible X causes Y.
Or you can experiment with people, but that is hard to come by because of ethical constraints. That is why most of what we know about human health is correlational and anecdotal.
Correlational evidence is when you study the population at large and notice that correlations between X and Y. This type of evidence does not support any conclusion of causation, because it is possible that a third variable, Z, actually causes both X and Y.
Anecdotal evidence is when you hear about X causing Y in one person, or 200 persons, or 5000 persons. It is not scientific because there was no randomization and no control comparisons. We don't know if X "caused" Y in these people because of some common factor Z that they all share, and that it is really Z causing both X and Y.
Most of the evidence supporting homeopathy would be considered anecdotal by the scientific community. However, just because something is anecdotal doesn't mean it isn't true. It just means, without experimental data, that there isn't yet any scientific proof that it is true.
I hope that clarifies what I mean when I use these terms.
Best,
Helen