Commercial concerns Research is expensive. Much of it is paid for by industrial companies who naturally want to show their product in the best light possible. Likewise researchers may not wish to displease their sponsors by presenting poor results as this may jeopardise future research income. 1 in 20 patients. Final comments Useful caveats Use confidence and descriptive statistics for everything except prospective, randomised, controlled studies.
All scores are non-parametric by definition eg.
I can recommend two very useful books on statistics.