-1- Statistical hypothesis testing Adriana Albu , Loredana Ungureanu Politehnica University Timisoara, ******@ Politehnica University Timisoara, ******@ Abstract In this article, we present a Bayesian statistical hypothesis testing inspection, testing theory and the process Mentioned hypothesis testing in the real world and the importance of, and essful test of the Notes. Key words Bayesian hypothesis testing ; Bayesian inference ; Test of significance Introduction A statistical hypothesis test isa method of making decisions using data, whether from a controlled experiment or an observational study (not controlled). In statistics ,a result is called statistically significant if it is unlikely to have occurred by chance alone, according toa pre-determined threshold probability, the significance level . The phrase "test of significance" was coined by Ronald Fisher : "Critical tests of this kind may be called tests of significance, and when such tests are available we may discover whether a second sample isor isnot significantly different from the first." [1] Hypothesis testing is sometimes called confirmatory data analysis , in contrast to exploratory data analysis . In frequency probability , these decisions are almost always made using null-hypothesis tests. These are tests that answer the question Assuming that the null hypothesis is true, what is the