It's interesting that they bring up Colin Powell in this, particularly because the big 'flaw' with this type of advice is lies in something that Donald Rumsfeld

It's interesting that they bring up Colin Powell in this, particularly because the big 'flaw' with this type of advice is lies in something that Donald Rumsfeld is infamous for saying - his so called 'known knowns' (or conversely, unknown unknown) phrase. You're ability to even judge that you have 40 to 70 percent of the information required isn't even a given. In particular, especially with something like medicine, where there is time pressure, bizarre individual circumstances, confounding issues, it can make it difficult to really compress your current state of knowledge into a single value representing percentage of 'known' information. That said, hilariously if you look at the reproduced slide in the bottom, the blog post and the slide actually say different things. Colin Powell says to act when you have between a 40 to 70 percent chance of being right given your current state of knowledge/information. The slide says acts when you have 40 to 70 percent of the necessary information.