Other educational reforms may have larger effects on students' test scores. Unfortunately, nobody is conducting the necessary research to find out if this is so, or even to learn which solutions hold the most promise. Admittedly, randomized experiments are not always possible. It would not be ethical to assign individuals randomly to groups, then ask the members of one group to smoke and the members of the second group to refrain. As a result, the only way to estimate the relationship between smoking and cancer is to take into account statistically all the other factors that might cause cancer.
Similar issues arise in education.
But in the absence of randomized experiments, no one really knows whether these findings are correct. Certainly, not all R.F.T.'s produce clear results. The experiments may be designed badly, the researchers may not collect the relevant data, or the subjects who can be studied may differ too much from ordinary people for the results to be useful. We cannot ignore these issues, but the answer is not to forgo random experiments. But this brings up the matter of cost, perhaps the biggest obstacle to widespread use of R.F.T.'s.