Listen to Danielle and Guido while during their short recap of the Magento User Group in Rotterdam. Danielle came all the way from the USA to talk about UX design for your webshop and Guido hosted a session about A/B testing.
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.