Abstract: Controlled experiments such as A/B tests are a gold standard for determining whether changes to a website significantly impacted user behaviour, however they are not always possible. In this talk we walk through a iPython Notebook and describe a non-parametric method for determining whether changes to e-commerce product pages impacted conversion to basket without the use of controlled experiments. For more details: https://pretalx.com/pycon-sweden-2021/talk/7FCJMW/ Speaker: Emir Uz