Look at their example. Theory: "One example in which triangulation has helped is in establishing that smoking during pregnancy results in babies with lower bir

Look at their example. Theory: "One example in which triangulation has helped is in establishing that smoking during pregnancy results in babies with lower birth weights" Lines of evidence: 1) "women who smoke are more likely to have babies who weigh less" 2) "if a woman’s partner smokes during her pregnancy, many of the same confounders apply as in maternal smoking, but the association with lower birth weight is much weaker" 3) "Birth weight can also be analysed according to levels of cigarette taxation across US states, which reduces the effects of confounders." 4) "the birth weights of siblings whose mother smoked during one pregnancy but not another." 5) "In cohorts grouped according to whether or not people carry a genetic variant associated with greater cigarette consumption in those who smoke, mothers who smoke and carry the variant tended to have babies who weighed less; non-smokers with the same variant did not." Conclusion: "Taken together, these studies make it clear that maternal smoking affects birth weight directly" This looks exactly like what I described as "counting heads". There is no synthesis of this evidence, just a disconnected list of things (and who knows whether contrary evidence has been left out or never checked).