about extrapolating beyond natural experiments
, when Klausner urges
To sum up, this work answers the broad question "do natural experiments
provide valid estimates in Political Science?"
Here again was a critical role for the natural experiment
. In Darwin's case, his interpretation of what happens to finches when they are isolated from each other on different islands of the Galapagos, is one of the best known natural experiments
in all of science.
The results of simulations obtained using numerical finite element models match the findings of natural experiments
. Making adjustments in describing materials and technological connections is sufficient for a description of damages to deformation zone elements.
Essayes of Natural Experiments
. NY: Johnson Reprint Corp.
Altogether, these three natural experiments
and one statistical study yield 15 tests of college selection.
Another problem with relying on natural experiments
is that comparisons of their results with longstanding practices rarely present sharp contrasts.
Deliberate experiments are substitutes for natural experiments
. Hence, the incidence of natural experiments
arising from exogenous shocks influences the value of intentional experiments.
Originally, we had in mind to consider only randomised or natural experiments
and quasi-experiments where important intervening variables had been controlled for that went beyond what one usually finds in criminal records (such as number and kind of previous convictions and offences, plus age and gender); in particular, we thought that a certain number of studies might have considered also education, employment record and drug or alcohol abuse history.
Instead, quasi-experiments and natural experiments
can be used to test ICT products.
Seven were randomized controlled trials (RCTs) and 10 controlled clinical trials (CCTs) or natural experiments
. Twenty-two studies went on to further analysis based on a set of criteria.
Historical evidence from "natural experiments
," such as the 1770 Saint-Domingue epidemic, should be considered in public health efforts to prevent disease re-emergence and increase awareness about bioterrorism potential.