Ignaz Semmelweis was a doctor who was instrumental to combat the childbed fever as well as many other illnesses by introducing hand washing with a chlorine solution between patients, most particular after autopsy that was performed during the day. However as an administrator and a doctor he was rejected as he clearly showed all signs of not being a gentlemen. The belief was that no gentleman could transmit any disease in the same way as today we are told that political will only act for the common good, no farmer will an animal, no banker will try anything unethical and so on. so we have the tendency to reject evidence and instead rely on established norms. Usually the sort is told to tell us how primitive and stupid most people were in former days, but I deliberately added a bit of modern analogy in it to show that the Semmelweis effect is not limited to a given time.
Service Orientated Architecture is a classic example how this effect operates. Once a lot of senior people are convinced that SOA is the next best thing to sliced bread they have the tendency to reject any argument against it. However in the same way someone like me is likely to reject all new ideas as false, as I will argue that nothing new has emerged since the late 80s when OO and Non SQL hit. Of course this is why I need to be aware of the Semmelweis effect on my own thinking. So the last trend I have seen as promising and new was the container system a la Docker that would host an environment without the usual overhead, as well as some promising cultural descriptors useful for enterprise architecture.
As architects we all need to careful to watch out for our own specific Semmelweis effect as we all have a tendency to condemn past mistakes by others, but less the tendency for real self critic which is the only way to realistic overcome the effect. For this we need constantly to examine all the hidden assumptions. I usually do this when I am forced to review assumptions on a project management form. While it is easy to put anything into those forms as long as it is remotely plausible, I usually take the time to check for the obvious or the the assumptions that are obvious to anyone but to me. As such I have found the best way to avoid the Semmelweis effect that we all fall victim to unless we are constantly watching out for it. Ignaz Semmelweis himself also felt on his own effect later when he tried to up the amount on chlorine and created a lot of grief with it, so we may be stars at a certain time in pointing out the obvious, but we still need to constantly aware for not falling for it.