This video is about the session Fabian and I did at the Magento Unconference in The Netherlands on October 16th 2016.
Our talk was about giving talks at events/(un)conferences and we also mentioned/showed this video about how to sound smart at a TedX talk: https://www.youtube.com/shared?ci=iM0Sw5KAWWE
Recently I've seen some (often absolute) statements going around, generally in the line of "open source commerce platforms are a terrible idea". Now of course different solutions always have different pros and cons.
A hierarchy of evidence (or levels of evidence) is a heuristic used to rank the relative strength of results obtained from scientific research. I've created a version of this chart/pyramid applied to CRO which you can see below. It contains the options we have as optimizers and tools and methods we often use to gather data.