The 4 types of patients we can only distinguish in Lake Wobegon- II

In practice, you cannot use data from a standard RCT to classify patients into these 4 buckets because we only ever observe outcome under placebo, R(0) or outcome under treatment R(1) but never both at the same time.

• Always responders and treatment responders can’t be distinguished

• Always responders and placebo responders can’t be distinguished.