Type I and Type II Error

 Hypothesis 

    Proposition that serves as a starting point for further investigation.

   Null Hypothesis

    Assumption that any differences between groups in your study occurred purely by a chance.

    How to set a clinical trial ?

    Identify a problem.

    Ask a scientific question - define null hypothesis to test. 

    Design a study.

            define population

            methodology of study

            power analysis

            define outcome measures

     Ethical approval

     Register trial and conduct

      Recruit patient

       Analyze results

       Interpret the findings.

Type I error or alpha error

        A null hypothesis that is true is falsely rejected or p-value suggests there is significant difference             when there is not.

   Type II or Beta Error

        confirms an idea that should have been rejected (failing to reject the null hypothesis)