How Many Users Do I Need For Testing?

The UX Usability Podcast - A podcast by theusabilitypodcast

Book: The Tao of Statistics: https://www.amazon.co.uk/gp/product/148337792X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=148337792X&linkCode=as2&tag=usergendesign-21&linkId=8fb6b7d0be4a43404a9b0be10851f26a