It was the same reading I had. "How are they doing double blinded experiments on typing?" comes across as assuming double blinded experiments are the only acce

It was the same reading I had. "How are they doing double blinded experiments on typing?" comes across as assuming double blinded experiments are the only acceptable way to a valid answer. Why can't single-blinded, or even unblinded, give useful answers? That is, why do you think any answer to your question would make a difference as to the quality of the results? Epidemiology is an important field of science, even when based on observational and not experimental science. The answer to "How are they doing double blinded experiments on observational studies" is "they aren't." Yet it's still good science.